Bitcoin Hash Functions Explained - CoinDesk

Satoshi originally added a double hash function into Bitcoin, but nobody really understood the true purpose of this until recently when Craig explained what it actually was for

Satoshi originally added a double hash function into Bitcoin, but nobody really understood the true purpose of this until recently when Craig explained what it actually was for submitted by UndercoverPatriot to CraigIsSatoshi [link] [comments]

Ultimate glossary of crypto currency terms, acronyms and abbreviations

I thought it would be really cool to have an ultimate guide for those new to crypto currencies and the terms used. I made this mostly for beginner’s and veterans alike. I’m not sure how much use you will get out of this. Stuff gets lost on Reddit quite easily so I hope this finds its way to you. Included in this list, I have included most of the terms used in crypto-communities. I have compiled this list from a multitude of sources. The list is in alphabetical order and may include some words/terms not exclusive to the crypto world but may be helpful regardless.
2FA
Two factor authentication. I highly advise that you use it.
51% Attack:
A situation where a single malicious individual or group gains control of more than half of a cryptocurrency network’s computing power. Theoretically, it could allow perpetrators to manipulate the system and spend the same coin multiple times, stop other users from completing blocks and make conflicting transactions to a chain that could harm the network.
Address (or Addy):
A unique string of numbers and letters (both upper and lower case) used to send, receive or store cryptocurrency on the network. It is also the public key in a pair of keys needed to sign a digital transaction. Addresses can be shared publicly as a text or in the form of a scannable QR code. They differ between cryptocurrencies. You can’t send Bitcoin to an Ethereum address, for example.
Altcoin (alternative coin): Any digital currency other than Bitcoin. These other currencies are alternatives to Bitcoin regarding features and functionalities (e.g. faster confirmation time, lower price, improved mining algorithm, higher total coin supply). There are hundreds of altcoins, including Ether, Ripple, Litecoin and many many others.
AIRDROP:
An event where the investors/participants are able to receive free tokens or coins into their digital wallet.
AML: Defines Anti-Money Laundering laws**.**
ARBITRAGE:
Getting risk-free profits by trading (simultaneous buying and selling of the cryptocurrency) on two different exchanges which have different prices for the same asset.
Ashdraked:
Being Ashdraked is essentially a more detailed version of being Zhoutonged. It is when you lose all of your invested capital, but you do so specifically by shorting Bitcoin. The expression “Ashdraked” comes from a story of a Romanian cryptocurrency investor who insisted upon shorting BTC, as he had done so successfully in the past. When the price of BTC rose from USD 300 to USD 500, the Romanian investor lost all of his money.
ATH (All Time High):
The highest price ever achieved by a cryptocurrency in its entire history. Alternatively, ATL is all time low
Bearish:
A tendency of prices to fall; a pessimistic expectation that the value of a coin is going to drop.
Bear trap:
A manipulation of a stock or commodity by investors.
Bitcoin:
The very first, and the highest ever valued, mass-market open source and decentralized cryptocurrency and digital payment system that runs on a worldwide peer to peer network. It operates independently of any centralized authorities
Bitconnect:
One of the biggest scams in the crypto world. it was made popular in the meme world by screaming idiot Carlos Matos, who infamously proclaimed," hey hey heeeey” and “what's a what's a what's up wasssssssssuuuuuuuuuuuuup, BitConneeeeeeeeeeeeeeeeeeeeeeeect!”. He is now in the mentally ill meme hall of fame.
Block:
A package of permanently recorded data about transactions occurring every time period (typically about 10 minutes) on the blockchain network. Once a record has been completed and verified, it goes into a blockchain and gives way to the next block. Each block also contains a complex mathematical puzzle with a unique answer, without which new blocks can’t be added to the chain.
Blockchain:
An unchangeable digital record of all transactions ever made in a particular cryptocurrency and shared across thousands of computers worldwide. It has no central authority governing it. Records, or blocks, are chained to each other using a cryptographic signature. They are stored publicly and chronologically, from the genesis block to the latest block, hence the term blockchain. Anyone can have access to the database and yet it remains incredibly difficult to hack.
Bullish:
A tendency of prices to rise; an optimistic expectation that a specific cryptocurrency will do well and its value is going to increase.
BTFD:
Buy the fucking dip. This advise was bestowed upon us by the gods themselves. It is the iron code to crypto enthusiasts.
Bull market:
A market that Cryptos are going up.
Consensus:
An agreement among blockchain participants on the validity of data. Consensus is reached when the majority of nodes on the network verify that the transaction is 100% valid.
Crypto bubble:
The instability of cryptocurrencies in terms of price value
Cryptocurrency:
A type of digital currency, secured by strong computer code (cryptography), that operates independently of any middlemen or central authoritie
Cryptography:
The art of converting sensitive data into a format unreadable for unauthorized users, which when decoded would result in a meaningful statement.
Cryptojacking:
The use of someone else’s device and profiting from its computational power to mine cryptocurrency without their knowledge and consent.
Crypto-Valhalla:
When HODLers(holders) eventually cash out they go to a place called crypto-Valhalla. The strong will be separated from the weak and the strong will then be given lambos.
DAO:
Decentralized Autonomous Organizations. It defines A blockchain technology inspired organization or corporation that exists and operates without human intervention.
Dapp (decentralized application):
An open-source application that runs and stores its data on a blockchain network (instead of a central server) to prevent a single failure point. This software is not controlled by the single body – information comes from people providing other people with data or computing power.
Decentralized:
A system with no fundamental control authority that governs the network. Instead, it is jointly managed by all users to the system.
Desktop wallet:
A wallet that stores the private keys on your computer, which allow the spending and management of your bitcoins.
DILDO:
Long red or green candles. This is a crypto signal that tells you that it is not favorable to trade at the moment. Found on candlestick charts.
Digital Signature:
An encrypted digital code attached to an electronic document to prove that the sender is who they say they are and confirm that a transaction is valid and should be accepted by the network.
Double Spending:
An attack on the blockchain where a malicious user manipulates the network by sending digital money to two different recipients at exactly the same time.
DYOR:
Means do your own research.
Encryption:
Converting data into code to protect it from unauthorized access, so that only the intended recipient(s) can decode it.
Eskrow:
the practice of having a third party act as an intermediary in a transaction. This third party holds the funds on and sends them off when the transaction is completed.
Ethereum:
Ethereum is an open source, public, blockchain-based platform that runs smart contracts and allows you to build dapps on it. Ethereum is fueled by the cryptocurrency Ether.
Exchange:
A platform (centralized or decentralized) for exchanging (trading) different forms of cryptocurrencies. These exchanges allow you to exchange cryptos for local currency. Some popular exchanges are Coinbase, Bittrex, Kraken and more.
Faucet:
A website which gives away free cryptocurrencies.
Fiat money:
Fiat currency is legal tender whose value is backed by the government that issued it, such as the US dollar or UK pound.
Fork:
A split in the blockchain, resulting in two separate branches, an original and a new alternate version of the cryptocurrency. As a single blockchain forks into two, they will both run simultaneously on different parts of the network. For example, Bitcoin Cash is a Bitcoin fork.
FOMO:
Fear of missing out.
Frictionless:
A system is frictionless when there are zero transaction costs or trading retraints.
FUD:
Fear, Uncertainty and Doubt regarding the crypto market.
Gas:
A fee paid to run transactions, dapps and smart contracts on Ethereum.
Halving:
A 50% decrease in block reward after the mining of a pre-specified number of blocks. Every 4 years, the “reward” for successfully mining a block of bitcoin is reduced by half. This is referred to as “Halving”.
Hardware wallet:
Physical wallet devices that can securely store cryptocurrency maximally. Some examples are Ledger Nano S**,** Digital Bitbox and more**.**
Hash:
The process that takes input data of varying sizes, performs an operation on it and converts it into a fixed size output. It cannot be reversed.
Hashing:
The process by which you mine bitcoin or similar cryptocurrency, by trying to solve the mathematical problem within it, using cryptographic hash functions.
HODL:
A Bitcoin enthusiast once accidentally misspelled the word HOLD and it is now part of the bitcoin legend. It can also mean hold on for dear life.
ICO (Initial Coin Offering):
A blockchain-based fundraising mechanism, or a public crowd sale of a new digital coin, used to raise capital from supporters for an early stage crypto venture. Beware of these as there have been quite a few scams in the past.
John mcAfee:
A man who will one day eat his balls on live television for falsely predicting bitcoin going to 100k. He has also become a small meme within the crypto community for his outlandish claims.
JOMO:
Joy of missing out. For those who are so depressed about missing out their sadness becomes joy.
KYC:
Know your customer(alternatively consumer).
Lambo:
This stands for Lamborghini. A small meme within the investing community where the moment someone gets rich they spend their earnings on a lambo. One day we will all have lambos in crypto-valhalla.
Ledger:
Away from Blockchain, it is a book of financial transactions and balances. In the world of crypto, the blockchain functions as a ledger. A digital currency’s ledger records all transactions which took place on a certain block chain network.
Leverage:
Trading with borrowed capital (margin) in order to increase the potential return of an investment.
Liquidity:
The availability of an asset to be bought and sold easily, without affecting its market price.
of the coins.
Margin trading:
The trading of assets or securities bought with borrowed money.
Market cap/MCAP:
A short-term for Market Capitalization. Market Capitalization refers to the market value of a particular cryptocurrency. It is computed by multiplying the Price of an individual unit of coins by the total circulating supply.
Miner:
A computer participating in any cryptocurrency network performing proof of work. This is usually done to receive block rewards.
Mining:
The act of solving a complex math equation to validate a blockchain transaction using computer processing power and specialized hardware.
Mining contract:
A method of investing in bitcoin mining hardware, allowing anyone to rent out a pre-specified amount of hashing power, for an agreed amount of time. The mining service takes care of hardware maintenance, hosting and electricity costs, making it simpler for investors.
Mining rig:
A computer specially designed for mining cryptocurrencies.
Mooning:
A situation the price of a coin rapidly increases in value. Can also be used as: “I hope bitcoin goes to the moon”
Node:
Any computing device that connects to the blockchain network.
Open source:
The practice of sharing the source code for a piece of computer software, allowing it to be distributed and altered by anyone.
OTC:
Over the counter. Trading is done directly between parties.
P2P (Peer to Peer):
A type of network connection where participants interact directly with each other rather than through a centralized third party. The system allows the exchange of resources from A to B, without having to go through a separate server.
Paper wallet:
A form of “cold storage” where the private keys are printed onto a piece of paper and stored offline. Considered as one of the safest crypto wallets, the truth is that it majors in sweeping coins from your wallets.
Pre mining:
The mining of a cryptocurrency by its developers before it is released to the public.
Proof of stake (POS):
A consensus distribution algorithm which essentially rewards you based upon the amount of the coin that you own. In other words, more investment in the coin will leads to more gain when you mine with this protocol In Proof of Stake, the resource held by the “miner” is their stake in the currency.
PROOF OF WORK (POW) :
The competition of computers competing to solve a tough crypto math problem. The first computer that does this is allowed to create new blocks and record information.” The miner is then usually rewarded via transaction fees.
Protocol:
A standardized set of rules for formatting and processing data.
Public key / private key:
A cryptographic code that allows a user to receive cryptocurrencies into an account. The public key is made available to everyone via a publicly accessible directory, and the private key remains confidential to its respective owner. Because the key pair is mathematically related, whatever is encrypted with a public key may only be decrypted by its corresponding private key.
Pump and dump:
Massive buying and selling activity of cryptocurrencies (sometimes organized and to one’s benefit) which essentially result in a phenomenon where the significant surge in the value of coin followed by a huge crash take place in a short time frame.
Recovery phrase:
A set of phrases you are given whereby you can regain or access your wallet should you lose the private key to your wallets — paper, mobile, desktop, and hardware wallet. These phrases are some random 12–24 words. A recovery Phrase can also be called as Recovery seed, Seed Key, Recovery Key, or Seed Phrase.
REKT:
Referring to the word “wrecked”. It defines a situation whereby an investor or trader who has been ruined utterly following the massive losses suffered in crypto industry.
Ripple:
An alternative payment network to Bitcoin based on similar cryptography. The ripple network uses XRP as currency and is capable of sending any asset type.
ROI:
Return on investment.
Safu:
A crypto term for safe popularized by the Bizonnaci YouTube channel after the CEO of Binance tweeted
“Funds are safe."
“the exchage I use got hacked!”“Oh no, are your funds safu?”
“My coins better be safu!”


Sats/Satoshi:
The smallest fraction of a bitcoin is called a “satoshi” or “sat”. It represents one hundred-millionth of a bitcoin and is named after Satoshi Nakamoto.
Satoshi Nakamoto:
This was the pseudonym for the mysterious creator of Bitcoin.
Scalability:
The ability of a cryptocurrency to contain the massive use of its Blockchain.
Sharding:
A scaling solution for the Blockchain. It is generally a method that allows nodes to have partial copies of the complete blockchain in order to increase overall network performance and consensus speeds.
Shitcoin:
Coin with little potential or future prospects.
Shill:
Spreading buzz by heavily promoting a particular coin in the community to create awareness.
Short position:
Selling of a specific cryptocurrency with an expectation that it will drop in value.
Silk road:
The online marketplace where drugs and other illicit items were traded for Bitcoin. This marketplace is using accessed through “TOR”, and VPNs. In October 2013, a Silk Road was shut down in by the FBI.
Smart Contract:
Certain computational benchmarks or barriers that have to be met in turn for money or data to be deposited or even be used to verify things such as land rights.
Software Wallet:
A crypto wallet that exists purely as software files on a computer. Usually, software wallets can be generated for free from a variety of sources.
Solidity:
A contract-oriented coding language for implementing smart contracts on Ethereum. Its syntax is similar to that of JavaScript.
Stable coin:
A cryptocoin with an extremely low volatility that can be used to trade against the overall market.
Staking:
Staking is the process of actively participating in transaction validation (similar to mining) on a proof-of-stake (PoS) blockchain. On these blockchains, anyone with a minimum-required balance of a specific cryptocurrency can validate transactions and earn Staking rewards.
Surge:
When a crypto currency appreciates or goes up in price.
Tank:
The opposite of mooning. When a coin tanks it can also be described as crashing.
Tendies
For traders , the chief prize is “tendies” (chicken tenders, the treat an overgrown man-child receives for being a “Good Boy”) .
Token:
A unit of value that represents a digital asset built on a blockchain system. A token is usually considered as a “coin” of a cryptocurrency, but it really has a wider functionality.
TOR: “The Onion Router” is a free web browser designed to protect users’ anonymity and resist censorship. Tor is usually used surfing the web anonymously and access sites on the “Darkweb”.
Transaction fee:
An amount of money users are charged from their transaction when sending cryptocurrencies.
Volatility:
A measure of fluctuations in the price of a financial instrument over time. High volatility in bitcoin is seen as risky since its shifting value discourages people from spending or accepting it.
Wallet:
A file that stores all your private keys and communicates with the blockchain to perform transactions. It allows you to send and receive bitcoins securely as well as view your balance and transaction history.
Whale:
An investor that holds a tremendous amount of cryptocurrency. Their extraordinary large holdings allow them to control prices and manipulate the market.
Whitepaper:

A comprehensive report or guide made to understand an issue or help decision making. It is also seen as a technical write up that most cryptocurrencies provide to take a deep look into the structure and plan of the cryptocurrency/Blockchain project. Satoshi Nakamoto was the first to release a whitepaper on Bitcoin, titled “Bitcoin: A Peer-to-Peer Electronic Cash System” in late 2008.
And with that I finally complete my odyssey. I sincerely hope that this helped you and if you are new, I welcome you to crypto. If you read all of that I hope it increased, you in knowledge.
my final definition:
Crypto-Family:
A collection of all the HODLers and crypto fanatics. A place where all people alike unite over a love for crypto.
We are all in this together as we pioneer the new world that is crypto currency. I wish you a great day and Happy HODLing.
-u/flacciduck
feel free to comment words or terms that you feel should be included or about any errors I made.
Edit1:some fixes were made and added words.
submitted by flacciduck to CryptoCurrency [link] [comments]

Gridcoin 5.0.0.0-Mandatory "Fern" Release

https://github.com/gridcoin-community/Gridcoin-Research/releases/tag/5.0.0.0
Finally! After over ten months of development and testing, "Fern" has arrived! This is a whopper. 240 pull requests merged. Essentially a complete rewrite that was started with the scraper (the "neural net" rewrite) in "Denise" has now been completed. Practically the ENTIRE Gridcoin specific codebase resting on top of the vanilla Bitcoin/Peercoin/Blackcoin vanilla PoS code has been rewritten. This removes the team requirement at last (see below), although there are many other important improvements besides that.
Fern was a monumental undertaking. We had to encode all of the old rules active for the v10 block protocol in new code and ensure that the new code was 100% compatible. This had to be done in such a way as to clear out all of the old spaghetti and ring-fence it with tightly controlled class implementations. We then wrote an entirely new, simplified ruleset for research rewards and reengineered contracts (which includes beacon management, polls, and voting) using properly classed code. The fundamentals of Gridcoin with this release are now on a very sound and maintainable footing, and the developers believe the codebase as updated here will serve as the fundamental basis for Gridcoin's future roadmap.
We have been testing this for MONTHS on testnet in various stages. The v10 (legacy) compatibility code has been running on testnet continuously as it was developed to ensure compatibility with existing nodes. During the last few months, we have done two private testnet forks and then the full public testnet testing for v11 code (the new protocol which is what Fern implements). The developers have also been running non-staking "sentinel" nodes on mainnet with this code to verify that the consensus rules are problem-free for the legacy compatibility code on the broader mainnet. We believe this amount of testing is going to result in a smooth rollout.
Given the amount of changes in Fern, I am presenting TWO changelogs below. One is high level, which summarizes the most significant changes in the protocol. The second changelog is the detailed one in the usual format, and gives you an inkling of the size of this release.

Highlights

Protocol

Note that the protocol changes will not become active until we cross the hard-fork transition height to v11, which has been set at 2053000. Given current average block spacing, this should happen around October 4, about one month from now.
Note that to get all of the beacons in the network on the new protocol, we are requiring ALL beacons to be validated. A two week (14 day) grace period is provided by the code, starting at the time of the transition height, for people currently holding a beacon to validate the beacon and prevent it from expiring. That means that EVERY CRUNCHER must advertise and validate their beacon AFTER the v11 transition (around Oct 4th) and BEFORE October 18th (or more precisely, 14 days from the actual date of the v11 transition). If you do not advertise and validate your beacon by this time, your beacon will expire and you will stop earning research rewards until you advertise and validate a new beacon. This process has been made much easier by a brand new beacon "wizard" that helps manage beacon advertisements and renewals. Once a beacon has been validated and is a v11 protocol beacon, the normal 180 day expiration rules apply. Note, however, that the 180 day expiration on research rewards has been removed with the Fern update. This means that while your beacon might expire after 180 days, your earned research rewards will be retained and can be claimed by advertising a beacon with the same CPID and going through the validation process again. In other words, you do not lose any earned research rewards if you do not stake a block within 180 days and keep your beacon up-to-date.
The transition height is also when the team requirement will be relaxed for the network.

GUI

Besides the beacon wizard, there are a number of improvements to the GUI, including new UI transaction types (and icons) for staking the superblock, sidestake sends, beacon advertisement, voting, poll creation, and transactions with a message. The main screen has been revamped with a better summary section, and better status icons. Several changes under the hood have improved GUI performance. And finally, the diagnostics have been revamped.

Blockchain

The wallet sync speed has been DRASTICALLY improved. A decent machine with a good network connection should be able to sync the entire mainnet blockchain in less than 4 hours. A fast machine with a really fast network connection and a good SSD can do it in about 2.5 hours. One of our goals was to reduce or eliminate the reliance on snapshots for mainnet, and I think we have accomplished that goal with the new sync speed. We have also streamlined the in-memory structures for the blockchain which shaves some memory use.
There are so many goodies here it is hard to summarize them all.
I would like to thank all of the contributors to this release, but especially thank @cyrossignol, whose incredible contributions formed the backbone of this release. I would also like to pay special thanks to @barton2526, @caraka, and @Quezacoatl1, who tirelessly helped during the testing and polishing phase on testnet with testing and repeated builds for all architectures.
The developers are proud to present this release to the community and we believe this represents the starting point for a true renaissance for Gridcoin!

Summary Changelog

Accrual

Changed

Most significantly, nodes calculate research rewards directly from the magnitudes in EACH superblock between stakes instead of using a two- or three- point average based on a CPID's current magnitude and the magnitude for the CPID when it last staked. For those long-timers in the community, this has been referred to as "Superblock Windows," and was first done in proof-of-concept form by @denravonska.

Removed

Beacons

Added

Changed

Removed

Unaltered

As a reminder:

Superblocks

Added

Changed

Removed

Voting

Added

Changed

Removed

Detailed Changelog

[5.0.0.0] 2020-09-03, mandatory, "Fern"

Added

Changed

Removed

Fixed

submitted by jamescowens to gridcoin [link] [comments]

Dragonchain Great Reddit Scaling Bake-Off Public Proposal

Dragonchain Great Reddit Scaling Bake-Off Public Proposal

Dragonchain Public Proposal TL;DR:

Dragonchain has demonstrated twice Reddit’s entire total daily volume (votes, comments, and posts per Reddit 2019 Year in Review) in a 24-hour demo on an operational network. Every single transaction on Dragonchain is decentralized immediately through 5 levels of Dragon Net, and then secured with combined proof on Bitcoin, Ethereum, Ethereum Classic, and Binance Chain, via Interchain. At the time, in January 2020, the entire cost of the demo was approximately $25K on a single system (transaction fees locked at $0.0001/txn). With current fees (lowest fee $0.0000025/txn), this would cost as little as $625.
Watch Joe walk through the entire proposal and answer questions on YouTube.
This proposal is also available on the Dragonchain blog.

Hello Reddit and Ethereum community!

I’m Joe Roets, Founder & CEO of Dragonchain. When the team and I first heard about The Great Reddit Scaling Bake-Off we were intrigued. We believe we have the solutions Reddit seeks for its community points system and we have them at scale.
For your consideration, we have submitted our proposal below. The team at Dragonchain and I welcome and look forward to your technical questions, philosophical feedback, and fair criticism, to build a scaling solution for Reddit that will empower its users. Because our architecture is unlike other blockchain platforms out there today, we expect to receive many questions while people try to grasp our project. I will answer all questions here in this thread on Reddit, and I've answered some questions in the stream on YouTube.
We have seen good discussions so far in the competition. We hope that Reddit’s scaling solution will emerge from The Great Reddit Scaling Bake-Off and that Reddit will have great success with the implementation.

Executive summary

Dragonchain is a robust open source hybrid blockchain platform that has proven to withstand the passing of time since our inception in 2014. We have continued to evolve to harness the scalability of private nodes, yet take full advantage of the security of public decentralized networks, like Ethereum. We have a live, operational, and fully functional Interchain network integrating Bitcoin, Ethereum, Ethereum Classic, and ~700 independent Dragonchain nodes. Every transaction is secured to Ethereum, Bitcoin, and Ethereum Classic. Transactions are immediately usable on chain, and the first decentralization is seen within 20 seconds on Dragon Net. Security increases further to public networks ETH, BTC, and ETC within 10 minutes to 2 hours. Smart contracts can be written in any executable language, offering full freedom to existing developers. We invite any developer to watch the demo, play with our SDK’s, review open source code, and to help us move forward. Dragonchain specializes in scalable loyalty & rewards solutions and has built a decentralized social network on chain, with very affordable transaction costs. This experience can be combined with the insights Reddit and the Ethereum community have gained in the past couple of months to roll out the solution at a rapid pace.

Response and PoC

In The Great Reddit Scaling Bake-Off post, Reddit has asked for a series of demonstrations, requirements, and other considerations. In this section, we will attempt to answer all of these requests.

Live Demo

A live proof of concept showing hundreds of thousands of transactions
On Jan 7, 2020, Dragonchain hosted a 24-hour live demonstration during which a quarter of a billion (250 million+) transactions executed fully on an operational network. Every single transaction on Dragonchain is decentralized immediately through 5 levels of Dragon Net, and then secured with combined proof on Bitcoin, Ethereum, Ethereum Classic, and Binance Chain, via Interchain. This means that every single transaction is secured by, and traceable to these networks. An attack on this system would require a simultaneous attack on all of the Interchained networks.
24 hours in 4 minutes (YouTube):
24 hours in 4 minutes
The demonstration was of a single business system, and any user is able to scale this further, by running multiple systems simultaneously. Our goals for the event were to demonstrate a consistent capacity greater than that of Visa over an extended time period.
Tooling to reproduce our demo is available here:
https://github.com/dragonchain/spirit-bomb

Source Code

Source code (for on & off-chain components as well tooling used for the PoC). The source code does not have to be shared publicly, but if Reddit decides to use a particular solution it will need to be shared with Reddit at some point.

Scaling

How it works & scales

Architectural Scaling

Dragonchain’s architecture attacks the scalability issue from multiple angles. Dragonchain is a hybrid blockchain platform, wherein every transaction is protected on a business node to the requirements of that business or purpose. A business node may be held completely private or may be exposed or replicated to any level of exposure desired.
Every node has its own blockchain and is independently scalable. Dragonchain established Context Based Verification as its consensus model. Every transaction is immediately usable on a trust basis, and in time is provable to an increasing level of decentralized consensus. A transaction will have a level of decentralization to independently owned and deployed Dragonchain nodes (~700 nodes) within seconds, and full decentralization to BTC and ETH within minutes or hours. Level 5 nodes (Interchain nodes) function to secure all transactions to public or otherwise external chains such as Bitcoin and Ethereum. These nodes scale the system by aggregating multiple blocks into a single Interchain transaction on a cadence. This timing is configurable based upon average fees for each respective chain. For detailed information about Dragonchain’s architecture, and Context Based Verification, please refer to the Dragonchain Architecture Document.

Economic Scaling

An interesting feature of Dragonchain’s network consensus is its economics and scarcity model. Since Dragon Net nodes (L2-L4) are independent staking nodes, deployment to cloud platforms would allow any of these nodes to scale to take on a large percentage of the verification work. This is great for scalability, but not good for the economy, because there is no scarcity, and pricing would develop a downward spiral and result in fewer verification nodes. For this reason, Dragonchain uses TIME as scarcity.
TIME is calculated as the number of Dragons held, multiplied by the number of days held. TIME influences the user’s access to features within the Dragonchain ecosystem. It takes into account both the Dragon balance and length of time each Dragon is held. TIME is staked by users against every verification node and dictates how much of the transaction fees are awarded to each participating node for every block.
TIME also dictates the transaction fee itself for the business node. TIME is staked against a business node to set a deterministic transaction fee level (see transaction fee table below in Cost section). This is very interesting in a discussion about scaling because it guarantees independence for business implementation. No matter how much traffic appears on the entire network, a business is guaranteed to not see an increased transaction fee rate.

Scaled Deployment

Dragonchain uses Docker and Kubernetes to allow the use of best practices traditional system scaling. Dragonchain offers managed nodes with an easy to use web based console interface. The user may also deploy a Dragonchain node within their own datacenter or favorite cloud platform. Users have deployed Dragonchain nodes on-prem on Amazon AWS, Google Cloud, MS Azure, and other hosting platforms around the world. Any executable code, anything you can write, can be written into a smart contract. This flexibility is what allows us to say that developers with no blockchain experience can use any code language to access the benefits of blockchain. Customers have used NodeJS, Python, Java, and even BASH shell script to write smart contracts on Dragonchain.
With Docker containers, we achieve better separation of concerns, faster deployment, higher reliability, and lower response times.
We chose Kubernetes for its self-healing features, ability to run multiple services on one server, and its large and thriving development community. It is resilient, scalable, and automated. OpenFaaS allows us to package smart contracts as Docker images for easy deployment.
Contract deployment time is now bounded only by the size of the Docker image being deployed but remains fast even for reasonably large images. We also take advantage of Docker’s flexibility and its ability to support any language that can run on x86 architecture. Any image, public or private, can be run as a smart contract using Dragonchain.

Flexibility in Scaling

Dragonchain’s architecture considers interoperability and integration as key features. From inception, we had a goal to increase adoption via integration with real business use cases and traditional systems.
We envision the ability for Reddit, in the future, to be able to integrate alternate content storage platforms or other financial services along with the token.
  • LBRY - To allow users to deploy content natively to LBRY
  • MakerDAO to allow users to lend small amounts backed by their Reddit community points.
  • STORJ/SIA to allow decentralized on chain storage of portions of content. These integrations or any other are relatively easy to integrate on Dragonchain with an Interchain implementation.

Cost

Cost estimates (on-chain and off-chain) For the purpose of this proposal, we assume that all transactions are on chain (posts, replies, and votes).
On the Dragonchain network, transaction costs are deterministic/predictable. By staking TIME on the business node (as described above) Reddit can reduce transaction costs to as low as $0.0000025 per transaction.
Dragonchain Fees Table

Getting Started

How to run it
Building on Dragonchain is simple and requires no blockchain experience. Spin up a business node (L1) in our managed environment (AWS), run it in your own cloud environment, or on-prem in your own datacenter. Clear documentation will walk you through the steps of spinning up your first Dragonchain Level 1 Business node.
Getting started is easy...
  1. Download Dragonchain’s dctl
  2. Input three commands into a terminal
  3. Build an image
  4. Run it
More information can be found in our Get started documents.

Architecture
Dragonchain is an open source hybrid platform. Through Dragon Net, each chain combines the power of a public blockchain (like Ethereum) with the privacy of a private blockchain.
Dragonchain organizes its network into five separate levels. A Level 1, or business node, is a totally private blockchain only accessible through the use of public/private keypairs. All business logic, including smart contracts, can be executed on this node directly and added to the chain.
After creating a block, the Level 1 business node broadcasts a version stripped of sensitive private data to Dragon Net. Three Level 2 Validating nodes validate the transaction based on guidelines determined from the business. A Level 3 Diversity node checks that the level 2 nodes are from a diverse array of locations. A Level 4 Notary node, hosted by a KYC partner, then signs the validation record received from the Level 3 node. The transaction hash is ledgered to the Level 5 public chain to take advantage of the hash power of massive public networks.
Dragon Net can be thought of as a “blockchain of blockchains”, where every level is a complete private blockchain. Because an L1 can send to multiple nodes on a single level, proof of existence is distributed among many places in the network. Eventually, proof of existence reaches level 5 and is published on a public network.

API Documentation

APIs (on chain & off)

SDK Source

Nobody’s Perfect

Known issues or tradeoffs
  • Dragonchain is open source and even though the platform is easy enough for developers to code in any language they are comfortable with, we do not have so large a developer community as Ethereum. We would like to see the Ethereum developer community (and any other communities) become familiar with our SDK’s, our solutions, and our platform, to unlock the full potential of our Ethereum Interchain. Long ago we decided to prioritize both Bitcoin and Ethereum Interchains. We envision an ecosystem that encompasses different projects to give developers the ability to take full advantage of all the opportunities blockchain offers to create decentralized solutions not only for Reddit but for all of our current platforms and systems. We believe that together we will take the adoption of blockchain further. We currently have additional Interchain with Ethereum Classic. We look forward to Interchain with other blockchains in the future. We invite all blockchains projects who believe in decentralization and security to Interchain with Dragonchain.
  • While we only have 700 nodes compared to 8,000 Ethereum and 10,000 Bitcoin nodes. We harness those 18,000 nodes to scale to extremely high levels of security. See Dragonchain metrics.
  • Some may consider the centralization of Dragonchain’s business nodes as an issue at first glance, however, the model is by design to protect business data. We do not consider this a drawback as these nodes can make any, none, or all data public. Depending upon the implementation, every subreddit could have control of its own business node, for potential business and enterprise offerings, bringing new alternative revenue streams to Reddit.

Costs and resources

Summary of cost & resource information for both on-chain & off-chain components used in the PoC, as well as cost & resource estimates for further scaling. If your PoC is not on mainnet, make note of any mainnet caveats (such as congestion issues).
Every transaction on the PoC system had a transaction fee of $0.0001 (one-hundredth of a cent USD). At 256MM transactions, the demo cost $25,600. With current operational fees, the same demonstration would cost $640 USD.
For the demonstration, to achieve throughput to mimic a worldwide payments network, we modeled several clients in AWS and 4-5 business nodes to handle the traffic. The business nodes were tuned to handle higher throughput by adjusting memory and machine footprint on AWS. This flexibility is valuable to implementing a system such as envisioned by Reddit. Given that Reddit’s daily traffic (posts, replies, and votes) is less than half that of our demo, we would expect that the entire Reddit system could be handled on 2-5 business nodes using right-sized containers on AWS or similar environments.
Verification was accomplished on the operational Dragon Net network with over 700 independently owned verification nodes running around the world at no cost to the business other than paid transaction fees.

Requirements

Scaling

This PoC should scale to the numbers below with minimal costs (both on & off-chain). There should also be a clear path to supporting hundreds of millions of users.
Over a 5 day period, your scaling PoC should be able to handle:
*100,000 point claims (minting & distributing points) *25,000 subscriptions *75,000 one-off points burning *100,000 transfers
During Dragonchain’s 24 hour demo, the above required numbers were reached within the first few minutes.
Reddit’s total activity is 9000% more than Ethereum’s total transaction level. Even if you do not include votes, it is still 700% more than Ethereum’s current volume. Dragonchain has demonstrated that it can handle 250 million transactions a day, and it’s architecture allows for multiple systems to work at that level simultaneously. In our PoC, we demonstrate double the full capacity of Reddit, and every transaction was proven all the way to Bitcoin and Ethereum.
Reddit Scaling on Ethereum

Decentralization

Solutions should not depend on any single third-party provider. We prefer solutions that do not depend on specific entities such as Reddit or another provider, and solutions with no single point of control or failure in off-chain components but recognize there are numerous trade-offs to consider
Dragonchain’s architecture calls for a hybrid approach. Private business nodes hold the sensitive data while the validation and verification of transactions for the business are decentralized within seconds and secured to public blockchains within 10 minutes to 2 hours. Nodes could potentially be controlled by owners of individual subreddits for more organic decentralization.
  • Billing is currently centralized - there is a path to federation and decentralization of a scaled billing solution.
  • Operational multi-cloud
  • Operational on-premises capabilities
  • Operational deployment to any datacenter
  • Over 700 independent Community Verification Nodes with proof of ownership
  • Operational Interchain (Interoperable to Bitcoin, Ethereum, and Ethereum Classic, open to more)

Usability Scaling solutions should have a simple end user experience.

Users shouldn't have to maintain any extra state/proofs, regularly monitor activity, keep track of extra keys, or sign anything other than their normal transactions
Dragonchain and its customers have demonstrated extraordinary usability as a feature in many applications, where users do not need to know that the system is backed by a live blockchain. Lyceum is one of these examples, where the progress of academy courses is being tracked, and successful completion of courses is rewarded with certificates on chain. Our @Save_The_Tweet bot is popular on Twitter. When used with one of the following hashtags - #please, #blockchain, #ThankYou, or #eternalize the tweet is saved through Eternal to multiple blockchains. A proof report is available for future reference. Other examples in use are DEN, our decentralized social media platform, and our console, where users can track their node rewards, view their TIME, and operate a business node.
Examples:

Transactions complete in a reasonable amount of time (seconds or minutes, not hours or days)
All transactions are immediately usable on chain by the system. A transaction begins the path to decentralization at the conclusion of a 5-second block when it gets distributed across 5 separate community run nodes. Full decentralization occurs within 10 minutes to 2 hours depending on which interchain (Bitcoin, Ethereum, or Ethereum Classic) the transaction hits first. Within approximately 2 hours, the combined hash power of all interchained blockchains secures the transaction.

Free to use for end users (no gas fees, or fixed/minimal fees that Reddit can pay on their behalf)
With transaction pricing as low as $0.0000025 per transaction, it may be considered reasonable for Reddit to cover transaction fees for users.
All of Reddit's Transactions on Blockchain (month)
Community points can be earned by users and distributed directly to their Reddit account in batch (as per Reddit minting plan), and allow users to withdraw rewards to their Ethereum wallet whenever they wish. Withdrawal fees can be paid by either user or Reddit. This model has been operating inside the Dragonchain system since 2018, and many security and financial compliance features can be optionally added. We feel that this capability greatly enhances user experience because it is seamless to a regular user without cryptocurrency experience, yet flexible to a tech savvy user. With regard to currency or token transactions, these would occur on the Reddit network, verified to BTC and ETH. These transactions would incur the $0.0000025 transaction fee. To estimate this fee we use the monthly active Reddit users statista with a 60% adoption rate and an estimated 10 transactions per month average resulting in an approximate $720 cost across the system. Reddit could feasibly incur all associated internal network charges (mining/minting, transfer, burn) as these are very low and controllable fees.
Reddit Internal Token Transaction Fees

Reddit Ethereum Token Transaction Fees
When we consider further the Ethereum fees that might be incurred, we have a few choices for a solution.
  1. Offload all Ethereum transaction fees (user withdrawals) to interested users as they wish to withdraw tokens for external use or sale.
  2. Cover Ethereum transaction fees by aggregating them on a timed schedule. Users would request withdrawal (from Reddit or individual subreddits), and they would be transacted on the Ethereum network every hour (or some other schedule).
  3. In a combination of the above, customers could cover aggregated fees.
  4. Integrate with alternate Ethereum roll up solutions or other proposals to aggregate minting and distribution transactions onto Ethereum.

Bonus Points

Users should be able to view their balances & transactions via a blockchain explorer-style interface
From interfaces for users who have no knowledge of blockchain technology to users who are well versed in blockchain terms such as those present in a typical block explorer, a system powered by Dragonchain has flexibility on how to provide balances and transaction data to users. Transactions can be made viewable in an Eternal Proof Report, which displays raw data along with TIME staking information and traceability all the way to Bitcoin, Ethereum, and every other Interchained network. The report shows fields such as transaction ID, timestamp, block ID, multiple verifications, and Interchain proof. See example here.
Node payouts within the Dragonchain console are listed in chronological order and can be further seen in either Dragons or USD. See example here.
In our social media platform, Dragon Den, users can see, in real-time, their NRG and MTR balances. See example here.
A new influencer app powered by Dragonchain, Raiinmaker, breaks down data into a user friendly interface that shows coin portfolio, redeemed rewards, and social scores per campaign. See example here.

Exiting is fast & simple
Withdrawing funds on Dragonchain’s console requires three clicks, however, withdrawal scenarios with more enhanced security features per Reddit’s discretion are obtainable.

Interoperability Compatibility with third party apps (wallets/contracts/etc) is necessary.
Proven interoperability at scale that surpasses the required specifications. Our entire platform consists of interoperable blockchains connected to each other and traditional systems. APIs are well documented. Third party permissions are possible with a simple smart contract without the end user being aware. No need to learn any specialized proprietary language. Any code base (not subsets) is usable within a Docker container. Interoperable with any blockchain or traditional APIs. We’ve witnessed relatively complex systems built by engineers with no blockchain or cryptocurrency experience. We’ve also demonstrated the creation of smart contracts within minutes built with BASH shell and Node.js. Please see our source code and API documentation.

Scaling solutions should be extensible and allow third parties to build on top of it Open source and extensible
APIs should be well documented and stable

Documentation should be clear and complete
For full documentation, explore our docs, SDK’s, Github repo’s, architecture documents, original Disney documentation, and other links or resources provided in this proposal.

Third-party permissionless integrations should be possible & straightforward Smart contracts are Docker based, can be written in any language, use full language (not subsets), and can therefore be integrated with any system including traditional system APIs. Simple is better. Learning an uncommon or proprietary language should not be necessary.
Advanced knowledge of mathematics, cryptography, or L2 scaling should not be required. Compatibility with common utilities & toolchains is expected.
Dragonchain business nodes and smart contracts leverage Docker to allow the use of literally any language or executable code. No proprietary language is necessary. We’ve witnessed relatively complex systems built by engineers with no blockchain or cryptocurrency experience. We’ve also demonstrated the creation of smart contracts within minutes built with BASH shell and Node.js.

Bonus

Bonus Points: Show us how it works. Do you have an idea for a cool new use case for Community Points? Build it!

TIME

Community points could be awarded to Reddit users based upon TIME too, whereas the longer someone is part of a subreddit, the more community points someone naturally gained, even if not actively commenting or sharing new posts. A daily login could be required for these community points to be credited. This grants awards to readers too and incentivizes readers to create an account on Reddit if they browse the website often. This concept could also be leveraged to provide some level of reputation based upon duration and consistency of contribution to a community subreddit.

Dragon Den

Dragonchain has already built a social media platform that harnesses community involvement. Dragon Den is a decentralized community built on the Dragonchain blockchain platform. Dragon Den is Dragonchain’s answer to fake news, trolling, and censorship. It incentivizes the creation and evaluation of quality content within communities. It could be described as being a shareholder of a subreddit or Reddit in its entirety. The more your subreddit is thriving, the more rewarding it will be. Den is currently in a public beta and in active development, though the real token economy is not live yet. There are different tokens for various purposes. Two tokens are Lair Ownership Rights (LOR) and Lair Ownership Tokens (LOT). LOT is a non-fungible token for ownership of a specific Lair. LOT will only be created and converted from LOR.
Energy (NRG) and Matter (MTR) work jointly. Your MTR determines how much NRG you receive in a 24-hour period. Providing quality content, or evaluating content will earn MTR.

Security. Users have full ownership & control of their points.
All community points awarded based upon any type of activity or gift, are secured and provable to all Interchain networks (currently BTC, ETH, ETC). Users are free to spend and withdraw their points as they please, depending on the features Reddit wants to bring into production.

Balances and transactions cannot be forged, manipulated, or blocked by Reddit or anyone else
Users can withdraw their balance to their ERC20 wallet, directly through Reddit. Reddit can cover the fees on their behalf, or the user covers this with a portion of their balance.

Users should own their points and be able to get on-chain ERC20 tokens without permission from anyone else
Through our console users can withdraw their ERC20 rewards. This can be achieved on Reddit too. Here is a walkthrough of our console, though this does not show the quick withdrawal functionality, a user can withdraw at any time. https://www.youtube.com/watch?v=aNlTMxnfVHw

Points should be recoverable to on-chain ERC20 tokens even if all third-parties involved go offline
If necessary, signed transactions from the Reddit system (e.g. Reddit + Subreddit) can be sent to the Ethereum smart contract for minting.

A public, third-party review attesting to the soundness of the design should be available
To our knowledge, at least two large corporations, including a top 3 accounting firm, have conducted positive reviews. These reviews have never been made public, as Dragonchain did not pay or contract for these studies to be released.

Bonus points
Public, third-party implementation review available or in progress
See above

Compatibility with HSMs & hardware wallets
For the purpose of this proposal, all tokenization would be on the Ethereum network using standard token contracts and as such, would be able to leverage all hardware wallet and Ethereum ecosystem services.

Other Considerations

Minting/distributing tokens is not performed by Reddit directly
This operation can be automated by smart contract on Ethereum. Subreddits can if desired have a role to play.

One off point burning, as well as recurring, non-interactive point burning (for subreddit memberships) should be possible and scalable
This is possible and scalable with interaction between Dragonchain Reddit system and Ethereum token contract(s).

Fully open-source solutions are strongly preferred
Dragonchain is fully open source (see section on Disney release after conclusion).

Conclusion

Whether it is today, or in the future, we would like to work together to bring secure flexibility to the highest standards. It is our hope to be considered by Ethereum, Reddit, and other integrative solutions so we may further discuss the possibilities of implementation. In our public demonstration, 256 million transactions were handled in our operational network on chain in 24 hours, for the low cost of $25K, which if run today would cost $625. Dragonchain’s interoperable foundation provides the atmosphere necessary to implement a frictionless community points system. Thank you for your consideration of our proposal. We look forward to working with the community to make something great!

Disney Releases Blockchain Platform as Open Source

The team at Disney created the Disney Private Blockchain Platform. The system was a hybrid interoperable blockchain platform for ledgering and smart contract development geared toward solving problems with blockchain adoption and usability. All objective evaluation would consider the team’s output a success. We released a list of use cases that we explored in some capacity at Disney, and our input on blockchain standardization as part of our participation in the W3C Blockchain Community Group.
https://lists.w3.org/Archives/Public/public-blockchain/2016May/0052.html

Open Source

In 2016, Roets proposed to release the platform as open source to spread the technology outside of Disney, as others within the W3C group were interested in the solutions that had been created inside of Disney.
Following a long process, step by step, the team met requirements for release. Among the requirements, the team had to:
  • Obtain VP support and approval for the release
  • Verify ownership of the software to be released
  • Verify that no proprietary content would be released
  • Convince the organization that there was a value to the open source community
  • Convince the organization that there was a value to Disney
  • Offer the plan for ongoing maintenance of the project outside of Disney
  • Itemize competing projects
  • Verify no conflict of interest
  • Preferred license
  • Change the project name to not use the name Disney, any Disney character, or any other associated IP - proposed Dragonchain - approved
  • Obtain legal approval
  • Approval from corporate, parks, and other business units
  • Approval from multiple Disney patent groups Copyright holder defined by Disney (Disney Connected and Advanced Technologies)
  • Trademark searches conducted for the selected name Dragonchain
  • Obtain IT security approval
  • Manual review of OSS components conducted
  • OWASP Dependency and Vulnerability Check Conducted
  • Obtain technical (software) approval
  • Offer management, process, and financial plans for the maintenance of the project.
  • Meet list of items to be addressed before release
  • Remove all Disney project references and scripts
  • Create a public distribution list for email communications
  • Remove Roets’ direct and internal contact information
  • Create public Slack channel and move from Disney slack channels
  • Create proper labels for issue tracking
  • Rename internal private Github repository
  • Add informative description to Github page
  • Expand README.md with more specific information
  • Add information beyond current “Blockchains are Magic”
  • Add getting started sections and info on cloning/forking the project
  • Add installation details
  • Add uninstall process
  • Add unit, functional, and integration test information
  • Detail how to contribute and get involved
  • Describe the git workflow that the project will use
  • Move to public, non-Disney git repository (Github or Bitbucket)
  • Obtain Disney Open Source Committee approval for release
On top of meeting the above criteria, as part of the process, the maintainer of the project had to receive the codebase on their own personal email and create accounts for maintenance (e.g. Github) with non-Disney accounts. Given the fact that the project spanned multiple business units, Roets was individually responsible for its ongoing maintenance. Because of this, he proposed in the open source application to create a non-profit organization to hold the IP and maintain the project. This was approved by Disney.
The Disney Open Source Committee approved the application known as OSSRELEASE-10, and the code was released on October 2, 2016. Disney decided to not issue a press release.
Original OSSRELASE-10 document

Dragonchain Foundation

The Dragonchain Foundation was created on January 17, 2017. https://den.social/l/Dragonchain/24130078352e485d96d2125082151cf0/dragonchain-and-disney/
submitted by j0j0r0 to ethereum [link] [comments]

Technical: Confidential Transactions and Their Implementation Tradeoffs

As requested by estradata here: https://old.reddit.com/Bitcoin/comments/iylou9/what_are_some_of_the_latest_innovations_in_the/g6heez1/
It is a general issue that crops up at the extremes of cryptography, with quantum breaks being just one of the extremes of (classical) cryptography.

Computational vs Information-Theoretic

The dichotomy is between computationally infeasible vs informationally-theoretic infeasible. Basically:
Quantum breaks represent a possible reduction in computational infeasibility of certain things, but not information-theoretic infeasibility.
For example, suppose you want to know what 256-bit preimages map to 256-bit hashes. In theory, you just need to build a table with 2256 entries and start from 0x0000000000000000000000000000000000000000000000000000000000000000 and so on. This is computationally infeasible, but not information-theoretic infeasible.
However, suppose you want to know what preimages, of any size, map to 256-bit hashes. Since the preimages can be of any size, after finishing with 256-bit preimages, you have to proceed to 257-bit preimages. And so on. And there is no size limit, so you will literally never finish. Even if you lived forever, you would not complete it. This is information-theoretic infeasible.

Commitments

How does this relate to confidential transactions? Basically, every confidential transaction simply hides the value behind a homomorphic commitment. What is a homomorphic commitment? Okay, let's start with commitments. A commitment is something which lets you hide something, and later reveal what you hid. Until you reveal it, even if somebody has access to the commitment, they cannot reverse it to find out what you hid. This is called the "hiding property" of commitments. However, when you do reveal it (or "open the commitment"), then you cannot replace what you hid with some other thing. This is called the "binding property" of commitments.
For example, a hash of a preimage is a commitment. Suppose I want to commit to something. For example, I want to show that I can predict the future using the energy of a spare galaxy I have in my pocket. I can hide that something by hashing a description of the future. Then I can give the hash to you. You still cannot learn the future, because it's just a hash, and you can't reverse the hash ("hiding"). But suppose the future event occurs. I can reveal that I did, in fact, know the future. So I give you the description, and you hash it and compare it to the hash I gave earlier. Because of preimage resistance, I cannot retroactively change what I hid in the hash, so what I gave must have been known to me at the time that I gave you the commitment i..e. hash ("binding").

Homomorphic Commitments

A homomorphic commitment simply means that if I can do certain operations on preimages of the commitment scheme, there are certain operations on the commitments that would create similar ("homo") changes ("morphic") to the commitments. For example, suppose I have a magical function h() which is a homomorphic commitment scheme. It can hide very large (near 256-bit) numbers. Then if h() is homomorphic, there may be certain operations on numbers behind the h() that have homomorphisms after the h(). For example, I might have an operation <+> that is homomorphic in h() on +, or in other words, if I have two large numbers a and b, then h(a + b) = h(a) <+> h(b). + and <+> are different operations, but they are homomorphic to each other.
For example, elliptic curve scalars and points have homomorphic operations. Scalars (private keys) are "just" very large near-256-bit numbers, while points are a scalar times a standard generator point G. Elliptic curve operations exist where there is a <+> between points that is homomorphic on standard + on scalars, and a <*> between a scalar and a point that is homomorphic on standard * multiplication on scalars.
For example, suppose I have two large scalars a and b. I can use elliptic curve points as a commitment scheme: I can take a <*> G to generate a point A. It is hiding since nobody can learn what a is unless I reveal it (a and A can be used in standard ECDSA private-public key cryptography, with the scalar a as the private key and the point A as the public key, and the a cannot be derived even if somebody else knows A). Thus, it is hiding. At the same time, for a particular point A and standard generator point G, there is only one possible scalar a which when "multiplied" with G yields A. So scalars and elliptic curve points are a commitment scheme, with both hiding and binding properties.
Now, as mentioned there is a <+> operation on points that is homomorphic to the + operation on corresponding scalars. For example, suppose there are two scalars a and b. I can compute (a + b) <*> G to generate a particular point. But even if I don't know scalars a and b, but I do know points A = a <*> G and B = b <*> G, then I can use A <+> B to derive (a + b) <*> G (or equivalently, (a <*> G) <+> (b <*> G) == (a + b) <*> G). This makes points a homomorphic commitment scheme on scalars.

Confidential Transactions: A Sketch

This is useful since we can easily use the near-256-bit scalars in SECP256K1 elliptic curves to easily represent values in a monetary system, and hide those values by using a homomorphic commitment scheme. We can use the hiding property to prevent people from learning the values of the money we are sending and receiving.
Now, in a proper cryptocurrency, a normal, non-coinbase transaction does not create or destroy coins: the values of the input coins are equal to the value of the output coins. We can use a homomorphic commitment scheme. Suppose I have a transaction that consumes an input value a and creates two output values b and c. That is, a = b + c, i.e. the sum of all inputs a equals the sum of all outputs b and c. But remember, with a homomorphic commitment scheme like elliptic curve points, there exists a <+> operation on points that is homomorphic to the ordinary school-arithmetic + addition on large numbers. So, confidential transactions can use points a <*> G as input, and points b <*> G and c <*> G as output, and we can easily prove that a <*> G = (b <*> G) <+> (c <*> G) if a = b + c, without revealing a, b, or c to anyone.

Pedersen Commitments

Actually, we cannot just use a <*> G as a commitment scheme in practice. Remember, Bitcoin has a cap on the number of satoshis ever to be created, and it's less than 253 satoshis, which is fairly trivial. I can easily compute all values of a <*> G for all values of a from 0 to 253 and know which a <*> G corresponds to which actual amount a. So in confidential transactions, we cannot naively use a <*> G commitments, we need Pedersen commitments.
If you know what a "salt" is, then Pedersen commitments are fairly obvious. A "salt" is something you add to e.g. a password so that the hash of the password is much harder to attack. Humans are idiots and when asked to generate passwords, will output a password that takes less than 230 possibilities, which is fairly easy to grind. So what you do is that you "salt" a password by prepending a random string to it. You then hash the random string + password, and store the random string --- the salt --- together with the hash in your database. Then when somebody logs in, you take the password, prepend the salt, hash, and check if the hash matches with the in-database hash, and you let them log in. Now, with a hash, even if somebody copies your password database, the can't get the password. They're hashed. But with a salt, even techniques like rainbow tables make a hacker's life even harder. They can't hash a possible password and check every hash in your db for something that matches. Instead, if they get a possible password, they have to prepend each salt, hash, then compare. That greatly increases the computational needs of a hacker, which is why salts are good.
What a Pedersen commitment is, is a point a <*> H, where a is the actual value you commit to, plus <+> another point r <*> G. H here is a second standard generator point, different from G. The r is the salt in the Pedersen commitment. It makes it so that even if you show (a <*> H) <+> (r <*> G) to somebody, they can't grind all possible values of a and try to match it with your point --- they also have to grind r (just as with the password-salt example above). And r is much larger, it can be a true near-256-bit number that is the range of scalars in SECP256K1, whereas a is constrained to "reasonable" numbers of satoshi, which cannot exceed 21 million Bitcoins.
Now, in order to validate a transaction with input a and outputs b and c, you only have to prove a = b + c. Suppose we are hiding those amounts using Pedersen commitments. You have an input of amount a, and you know a and r. The blockchain has an amount (a <*> H) <+> (r <*> G). In order to create the two outputs b and c, you just have to create two new r scalars such that r = r[0] + r[1]. This is trivial, you just select a new random r[0] and then compute r[1] = r - r[0], it's just basic algebra.
Then you create a transaction consuming the input (a <*> H) <+> (r <*> G) and outputs (b <*> H) <+> (r[0] <*> G) and (c <*> H) <+> (r[1] <*> G). You know that a = b + c, and r = r[0] + r[1], while fullnodes around the world, who don't know any of the amounts or scalars involved, can just take the points (a <*> H) <+> (r <*> G) and see if it equals (b <*> H) <+> (r[0] <*> G) <+> (c <*> H) <+> (r[1] <*> G). That is all that fullnodes have to validate, they just need to perform <+> operations on points and comparison on points, and from there they validate transactions, all without knowing the actual values involved.

Computational Binding, Information-Theoretic Hiding

Like all commitments, Pedersen Commitments are binding and hiding.
However, there are really two kinds of commitments:
What does this mean? It's just a measure of how "impossible" binding vs hiding is. Pedersen commitments are computationally binding, meaning that in theory, a user of this commitment with arbitrary time and space and energy can, in theory, replace the amount with something else. However, it is information-theoretic hiding, meaning an attacker with arbitrary time and space and energy cannot figure out exactly what got hidden behind the commitment.
But why?
Now, we have been using a and a <*> G as private keys and public keys in ECDSA and Schnorr. There is an operation <*> on a scalar and a point that generates another point, but we cannot "revrese" this operation. For example, even if I know A, and know that A = a <*> G, but do not know a, I cannot derive a --- there is no operation between A G that lets me know a.
Actually there is: I "just" need to have so much time, space, and energy that I just start counting a from 0 to 2256 and find which a results in A = a <*> G. This is a computational limit: I don't have a spare universe in my back pocket I can use to do all those computations.
Now, replace a with h and A with H. Remember that Pedersen commitments use a "second" standard generator point. The generator points G and H are "not really special" --- they are just random points on the curve that we selected and standardized. There is no operation H G such that I can learn h where H = h <*> G, though if I happen to have a spare universe in my back pocket I can "just" brute force it.
Suppose I do have a spare universe in my back pocket, and learn h = H G such that H = h <*> G. What can I do in Pedersen commitments?
Well, I have an amount a that is committed to by (a <*> H) <+> (r <*> G). But I happen to know h! Suppose I want to double my money a without involving Elon Musk. Then:
That is what we mean by computationally binding: if I can compute h such that H = h <*> G, then I can find another number which opens the same commitment. And of course I'd make sure that number is much larger than what I originally had in that address!
Now, the reason why it is "only" computationally binding is that it is information-theoretically hiding. Suppose somebody knows h, but has no money in the cryptocurrency. All they see are points. They can try to find what the original amounts are, but because any amount can be mapped to "the same" point with knowledge of h (e.g. in the above, a and 2 * a got mapped to the same point by "just" replacing the salt r with r - a * h; this can be done for 3 * a, 4 * a etc.), they cannot learn historical amounts --- the a in historical amounts could be anything.
The drawback, though, is that --- as seen above --- arbitrary inflation is now introduced once somebody knows h. They can multiply their money by any arbitrary factor with knowledge of h.
It is impossible to have both perfect hiding (i.e. historical amounts remain hidden even after a computational break) and perfect binding (i.e. you can't later open the commitment to a different, much larger, amount).
Pedersen commitments just happen to have perfect hiding, but only computationally-infeasible binding. This means they allow hiding historical values, but in case of anything that allows better computational power --- including but not limited to quantum breaks --- they allow arbitrary inflation.

Changing The Tradeoffs with ElGamal Commitments

An ElGamal commitment is just a Pedersen commitment, but with the point r <*> G also stored in a separate section of the transaction.
This commits the r, and fixes it to a specific value. This prevents me from opening my (a <*> H) <+> (r <*> G) as ((2 * a) <*> H) <+> ((r - a * h) <*> G), because the (r - a * h) would not match the r <*> G sitting in a separate section of the transaction. This forces me to be bound to that specific value, and no amount of computation power will let me escape --- it is information-theoretically binding i.e. perfectly binding.
But that is now computationally hiding. An evil surveillor with arbitrary time and space can focus on the r <*> G sitting in a separate section of the transaction, and grind r from 0 to 2256 to determine what r matches that point. Then from there, they can negate r to get (-r) <*> G and add it to the (a <*> H) <+> (r <*> G) to get a <*> H, and then grind that to determine the value a. With massive increases in computational ability --- including but not limited to quantum breaks --- an evil surveillor can see all the historical amounts of confidential transactions.

Conclusion

This is the source of the tradeoff: either you design confidential transactions so in case of a quantum break, historical transactions continue to hide their amounts, but inflation of the money is now unavoidable, OR you make the money supply sacrosanct, but you potentially sacrifice amount hiding in case of some break, including but not limited to quantum breaks.
submitted by almkglor to Bitcoin [link] [comments]

Why i’m bullish on Zilliqa (long read)

Edit: TL;DR added in the comments
 
Hey all, I've been researching coins since 2017 and have gone through 100s of them in the last 3 years. I got introduced to blockchain via Bitcoin of course, analyzed Ethereum thereafter and from that moment I have a keen interest in smart contact platforms. I’m passionate about Ethereum but I find Zilliqa to have a better risk-reward ratio. Especially because Zilliqa has found an elegant balance between being secure, decentralized and scalable in my opinion.
 
Below I post my analysis of why from all the coins I went through I’m most bullish on Zilliqa (yes I went through Tezos, EOS, NEO, VeChain, Harmony, Algorand, Cardano etc.). Note that this is not investment advice and although it's a thorough analysis there is obviously some bias involved. Looking forward to what you all think!
 
Fun fact: the name Zilliqa is a play on ‘silica’ silicon dioxide which means “Silicon for the high-throughput consensus computer.”
 
This post is divided into (i) Technology, (ii) Business & Partnerships, and (iii) Marketing & Community. I’ve tried to make the technology part readable for a broad audience. If you’ve ever tried understanding the inner workings of Bitcoin and Ethereum you should be able to grasp most parts. Otherwise, just skim through and once you are zoning out head to the next part.
 
Technology and some more:
 
Introduction
 
The technology is one of the main reasons why I’m so bullish on Zilliqa. First thing you see on their website is: “Zilliqa is a high-performance, high-security blockchain platform for enterprises and next-generation applications.” These are some bold statements.
 
Before we deep dive into the technology let’s take a step back in time first as they have quite the history. The initial research paper from which Zilliqa originated dates back to August 2016: Elastico: A Secure Sharding Protocol For Open Blockchains where Loi Luu (Kyber Network) is one of the co-authors. Other ideas that led to the development of what Zilliqa has become today are: Bitcoin-NG, collective signing CoSi, ByzCoin and Omniledger.
 
The technical white paper was made public in August 2017 and since then they have achieved everything stated in the white paper and also created their own open source intermediate level smart contract language called Scilla (functional programming language similar to OCaml) too.
 
Mainnet is live since the end of January 2019 with daily transaction rates growing continuously. About a week ago mainnet reached 5 million transactions, 500.000+ addresses in total along with 2400 nodes keeping the network decentralized and secure. Circulating supply is nearing 11 billion and currently only mining rewards are left. The maximum supply is 21 billion with annual inflation being 7.13% currently and will only decrease with time.
 
Zilliqa realized early on that the usage of public cryptocurrencies and smart contracts were increasing but decentralized, secure, and scalable alternatives were lacking in the crypto space. They proposed to apply sharding onto a public smart contract blockchain where the transaction rate increases almost linear with the increase in the amount of nodes. More nodes = higher transaction throughput and increased decentralization. Sharding comes in many forms and Zilliqa uses network-, transaction- and computational sharding. Network sharding opens up the possibility of using transaction- and computational sharding on top. Zilliqa does not use state sharding for now. We’ll come back to this later.
 
Before we continue dissecting how Zilliqa achieves such from a technological standpoint it’s good to keep in mind that a blockchain being decentralised and secure and scalable is still one of the main hurdles in allowing widespread usage of decentralised networks. In my opinion this needs to be solved first before blockchains can get to the point where they can create and add large scale value. So I invite you to read the next section to grasp the underlying fundamentals. Because after all these premises need to be true otherwise there isn’t a fundamental case to be bullish on Zilliqa, right?
 
Down the rabbit hole
 
How have they achieved this? Let’s define the basics first: key players on Zilliqa are the users and the miners. A user is anybody who uses the blockchain to transfer funds or run smart contracts. Miners are the (shard) nodes in the network who run the consensus protocol and get rewarded for their service in Zillings (ZIL). The mining network is divided into several smaller networks called shards, which is also referred to as ‘network sharding’. Miners subsequently are randomly assigned to a shard by another set of miners called DS (Directory Service) nodes. The regular shards process transactions and the outputs of these shards are eventually combined by the DS shard as they reach consensus on the final state. More on how these DS shards reach consensus (via pBFT) will be explained later on.
 
The Zilliqa network produces two types of blocks: DS blocks and Tx blocks. One DS Block consists of 100 Tx Blocks. And as previously mentioned there are two types of nodes concerned with reaching consensus: shard nodes and DS nodes. Becoming a shard node or DS node is being defined by the result of a PoW cycle (Ethash) at the beginning of the DS Block. All candidate mining nodes compete with each other and run the PoW (Proof-of-Work) cycle for 60 seconds and the submissions achieving the highest difficulty will be allowed on the network. And to put it in perspective: the average difficulty for one DS node is ~ 2 Th/s equaling 2.000.000 Mh/s or 55 thousand+ GeForce GTX 1070 / 8 GB GPUs at 35.4 Mh/s. Each DS Block 10 new DS nodes are allowed. And a shard node needs to provide around 8.53 GH/s currently (around 240 GTX 1070s). Dual mining ETH/ETC and ZIL is possible and can be done via mining software such as Phoenix and Claymore. There are pools and if you have large amounts of hashing power (Ethash) available you could mine solo.
 
The PoW cycle of 60 seconds is a peak performance and acts as an entry ticket to the network. The entry ticket is called a sybil resistance mechanism and makes it incredibly hard for adversaries to spawn lots of identities and manipulate the network with these identities. And after every 100 Tx Blocks which corresponds to roughly 1,5 hour this PoW process repeats. In between these 1,5 hour, no PoW needs to be done meaning Zilliqa’s energy consumption to keep the network secure is low. For more detailed information on how mining works click here.
Okay, hats off to you. You have made it this far. Before we go any deeper down the rabbit hole we first must understand why Zilliqa goes through all of the above technicalities and understand a bit more what a blockchain on a more fundamental level is. Because the core of Zilliqa’s consensus protocol relies on the usage of pBFT (practical Byzantine Fault Tolerance) we need to know more about state machines and their function. Navigate to Viewblock, a Zilliqa block explorer, and just come back to this article. We will use this site to navigate through a few concepts.
 
We have established that Zilliqa is a public and distributed blockchain. Meaning that everyone with an internet connection can send ZILs, trigger smart contracts, etc. and there is no central authority who fully controls the network. Zilliqa and other public and distributed blockchains (like Bitcoin and Ethereum) can also be defined as state machines.
 
Taking the liberty of paraphrasing examples and definitions given by Samuel Brooks’ medium article, he describes the definition of a blockchain (like Zilliqa) as: “A peer-to-peer, append-only datastore that uses consensus to synchronize cryptographically-secure data”.
 
Next, he states that: "blockchains are fundamentally systems for managing valid state transitions”. For some more context, I recommend reading the whole medium article to get a better grasp of the definitions and understanding of state machines. Nevertheless, let’s try to simplify and compile it into a single paragraph. Take traffic lights as an example: all its states (red, amber, and green) are predefined, all possible outcomes are known and it doesn’t matter if you encounter the traffic light today or tomorrow. It will still behave the same. Managing the states of a traffic light can be done by triggering a sensor on the road or pushing a button resulting in one traffic lights’ state going from green to red (via amber) and another light from red to green.
 
With public blockchains like Zilliqa, this isn’t so straightforward and simple. It started with block #1 almost 1,5 years ago and every 45 seconds or so a new block linked to the previous block is being added. Resulting in a chain of blocks with transactions in it that everyone can verify from block #1 to the current #647.000+ block. The state is ever changing and the states it can find itself in are infinite. And while the traffic light might work together in tandem with various other traffic lights, it’s rather insignificant comparing it to a public blockchain. Because Zilliqa consists of 2400 nodes who need to work together to achieve consensus on what the latest valid state is while some of these nodes may have latency or broadcast issues, drop offline or are deliberately trying to attack the network, etc.
 
Now go back to the Viewblock page take a look at the amount of transaction, addresses, block and DS height and then hit refresh. Obviously as expected you see new incremented values on one or all parameters. And how did the Zilliqa blockchain manage to transition from a previous valid state to the latest valid state? By using pBFT to reach consensus on the latest valid state.
 
After having obtained the entry ticket, miners execute pBFT to reach consensus on the ever-changing state of the blockchain. pBFT requires a series of network communication between nodes, and as such there is no GPU involved (but CPU). Resulting in the total energy consumed to keep the blockchain secure, decentralized and scalable being low.
 
pBFT stands for practical Byzantine Fault Tolerance and is an optimization on the Byzantine Fault Tolerant algorithm. To quote Blockonomi: “In the context of distributed systems, Byzantine Fault Tolerance is the ability of a distributed computer network to function as desired and correctly reach a sufficient consensus despite malicious components (nodes) of the system failing or propagating incorrect information to other peers.” Zilliqa is such a distributed computer network and depends on the honesty of the nodes (shard and DS) to reach consensus and to continuously update the state with the latest block. If pBFT is a new term for you I can highly recommend the Blockonomi article.
 
The idea of pBFT was introduced in 1999 - one of the authors even won a Turing award for it - and it is well researched and applied in various blockchains and distributed systems nowadays. If you want more advanced information than the Blockonomi link provides click here. And if you’re in between Blockonomi and the University of Singapore read the Zilliqa Design Story Part 2 dating from October 2017.
Quoting from the Zilliqa tech whitepaper: “pBFT relies upon a correct leader (which is randomly selected) to begin each phase and proceed when the sufficient majority exists. In case the leader is byzantine it can stall the entire consensus protocol. To address this challenge, pBFT offers a view change protocol to replace the byzantine leader with another one.”
 
pBFT can tolerate ⅓ of the nodes being dishonest (offline counts as Byzantine = dishonest) and the consensus protocol will function without stalling or hiccups. Once there are more than ⅓ of dishonest nodes but no more than ⅔ the network will be stalled and a view change will be triggered to elect a new DS leader. Only when more than ⅔ of the nodes are dishonest (66%) double-spend attacks become possible.
 
If the network stalls no transactions can be processed and one has to wait until a new honest leader has been elected. When the mainnet was just launched and in its early phases, view changes happened regularly. As of today the last stalling of the network - and view change being triggered - was at the end of October 2019.
 
Another benefit of using pBFT for consensus besides low energy is the immediate finality it provides. Once your transaction is included in a block and the block is added to the chain it’s done. Lastly, take a look at this article where three types of finality are being defined: probabilistic, absolute and economic finality. Zilliqa falls under the absolute finality (just like Tendermint for example). Although lengthy already we skipped through some of the inner workings from Zilliqa’s consensus: read the Zilliqa Design Story Part 3 and you will be close to having a complete picture on it. Enough about PoW, sybil resistance mechanism, pBFT, etc. Another thing we haven’t looked at yet is the amount of decentralization.
 
Decentralisation
 
Currently, there are four shards, each one of them consisting of 600 nodes. 1 shard with 600 so-called DS nodes (Directory Service - they need to achieve a higher difficulty than shard nodes) and 1800 shard nodes of which 250 are shard guards (centralized nodes controlled by the team). The amount of shard guards has been steadily declining from 1200 in January 2019 to 250 as of May 2020. On the Viewblock statistics, you can see that many of the nodes are being located in the US but those are only the (CPU parts of the) shard nodes who perform pBFT. There is no data from where the PoW sources are coming. And when the Zilliqa blockchain starts reaching its transaction capacity limit, a network upgrade needs to be executed to lift the current cap of maximum 2400 nodes to allow more nodes and formation of more shards which will allow to network to keep on scaling according to demand.
Besides shard nodes there are also seed nodes. The main role of seed nodes is to serve as direct access points (for end-users and clients) to the core Zilliqa network that validates transactions. Seed nodes consolidate transaction requests and forward these to the lookup nodes (another type of nodes) for distribution to the shards in the network. Seed nodes also maintain the entire transaction history and the global state of the blockchain which is needed to provide services such as block explorers. Seed nodes in the Zilliqa network are comparable to Infura on Ethereum.
 
The seed nodes were first only operated by Zilliqa themselves, exchanges and Viewblock. Operators of seed nodes like exchanges had no incentive to open them for the greater public. They were centralised at first. Decentralisation at the seed nodes level has been steadily rolled out since March 2020 ( Zilliqa Improvement Proposal 3 ). Currently the amount of seed nodes is being increased, they are public-facing and at the same time PoS is applied to incentivize seed node operators and make it possible for ZIL holders to stake and earn passive yields. Important distinction: seed nodes are not involved with consensus! That is still PoW as entry ticket and pBFT for the actual consensus.
 
5% of the block rewards are being assigned to seed nodes (from the beginning in 2019) and those are being used to pay out ZIL stakers. The 5% block rewards with an annual yield of 10.03% translate to roughly 610 MM ZILs in total that can be staked. Exchanges use the custodial variant of staking and wallets like Moonlet will use the non-custodial version (starting in Q3 2020). Staking is being done by sending ZILs to a smart contract created by Zilliqa and audited by Quantstamp.
 
With a high amount of DS; shard nodes and seed nodes becoming more decentralized too, Zilliqa qualifies for the label of decentralized in my opinion.
 
Smart contracts
 
Let me start by saying I’m not a developer and my programming skills are quite limited. So I‘m taking the ELI5 route (maybe 12) but if you are familiar with Javascript, Solidity or specifically OCaml please head straight to Scilla - read the docs to get a good initial grasp of how Zilliqa’s smart contract language Scilla works and if you ask yourself “why another programming language?” check this article. And if you want to play around with some sample contracts in an IDE click here. The faucet can be found here. And more information on architecture, dapp development and API can be found on the Developer Portal.
If you are more into listening and watching: check this recent webinar explaining Zilliqa and Scilla. Link is time-stamped so you’ll start right away with a platform introduction, roadmap 2020 and afterwards a proper Scilla introduction.
 
Generalized: programming languages can be divided into being ‘object-oriented’ or ‘functional’. Here is an ELI5 given by software development academy: * “all programs have two basic components, data – what the program knows – and behavior – what the program can do with that data. So object-oriented programming states that combining data and related behaviors in one place, is called “object”, which makes it easier to understand how a particular program works. On the other hand, functional programming argues that data and behavior are different things and should be separated to ensure their clarity.” *
 
Scilla is on the functional side and shares similarities with OCaml: OCaml is a general-purpose programming language with an emphasis on expressiveness and safety. It has an advanced type system that helps catch your mistakes without getting in your way. It's used in environments where a single mistake can cost millions and speed matters, is supported by an active community, and has a rich set of libraries and development tools. For all its power, OCaml is also pretty simple, which is one reason it's often used as a teaching language.
 
Scilla is blockchain agnostic, can be implemented onto other blockchains as well, is recognized by academics and won a so-called Distinguished Artifact Award award at the end of last year.
 
One of the reasons why the Zilliqa team decided to create their own programming language focused on preventing smart contract vulnerabilities is that adding logic on a blockchain, programming, means that you cannot afford to make mistakes. Otherwise, it could cost you. It’s all great and fun blockchains being immutable but updating your code because you found a bug isn’t the same as with a regular web application for example. And with smart contracts, it inherently involves cryptocurrencies in some form thus value.
 
Another difference with programming languages on a blockchain is gas. Every transaction you do on a smart contract platform like Zilliqa or Ethereum costs gas. With gas you basically pay for computational costs. Sending a ZIL from address A to address B costs 0.001 ZIL currently. Smart contracts are more complex, often involve various functions and require more gas (if gas is a new concept click here ).
 
So with Scilla, similar to Solidity, you need to make sure that “every function in your smart contract will run as expected without hitting gas limits. An improper resource analysis may lead to situations where funds may get stuck simply because a part of the smart contract code cannot be executed due to gas limits. Such constraints are not present in traditional software systems”. Scilla design story part 1
 
Some examples of smart contract issues you’d want to avoid are: leaking funds, ‘unexpected changes to critical state variables’ (example: someone other than you setting his or her address as the owner of the smart contract after creation) or simply killing a contract.
 
Scilla also allows for formal verification. Wikipedia to the rescue: In the context of hardware and software systems, formal verification is the act of proving or disproving the correctness of intended algorithms underlying a system with respect to a certain formal specification or property, using formal methods of mathematics.
 
Formal verification can be helpful in proving the correctness of systems such as: cryptographic protocols, combinational circuits, digital circuits with internal memory, and software expressed as source code.
 
Scilla is being developed hand-in-hand with formalization of its semantics and its embedding into the Coq proof assistant — a state-of-the art tool for mechanized proofs about properties of programs.”
 
Simply put, with Scilla and accompanying tooling developers can be mathematically sure and proof that the smart contract they’ve written does what he or she intends it to do.
 
Smart contract on a sharded environment and state sharding
 
There is one more topic I’d like to touch on: smart contract execution in a sharded environment (and what is the effect of state sharding). This is a complex topic. I’m not able to explain it any easier than what is posted here. But I will try to compress the post into something easy to digest.
 
Earlier on we have established that Zilliqa can process transactions in parallel due to network sharding. This is where the linear scalability comes from. We can define simple transactions: a transaction from address A to B (Category 1), a transaction where a user interacts with one smart contract (Category 2) and the most complex ones where triggering a transaction results in multiple smart contracts being involved (Category 3). The shards are able to process transactions on their own without interference of the other shards. With Category 1 transactions that is doable, with Category 2 transactions sometimes if that address is in the same shard as the smart contract but with Category 3 you definitely need communication between the shards. Solving that requires to make a set of communication rules the protocol needs to follow in order to process all transactions in a generalised fashion.
 
And this is where the downsides of state sharding comes in currently. All shards in Zilliqa have access to the complete state. Yes the state size (0.1 GB at the moment) grows and all of the nodes need to store it but it also means that they don’t need to shop around for information available on other shards. Requiring more communication and adding more complexity. Computer science knowledge and/or developer knowledge required links if you want to dig further: Scilla - language grammar Scilla - Foundations for Verifiable Decentralised Computations on a Blockchain Gas Accounting NUS x Zilliqa: Smart contract language workshop
 
Easier to follow links on programming Scilla https://learnscilla.com/home Ivan on Tech
 
Roadmap / Zilliqa 2.0
 
There is no strict defined roadmap but here are topics being worked on. And via the Zilliqa website there is also more information on the projects they are working on.
 
Business & Partnerships
 
It’s not only technology in which Zilliqa seems to be excelling as their ecosystem has been expanding and starting to grow rapidly. The project is on a mission to provide OpenFinance (OpFi) to the world and Singapore is the right place to be due to its progressive regulations and futuristic thinking. Singapore has taken a proactive approach towards cryptocurrencies by introducing the Payment Services Act 2019 (PS Act). Among other things, the PS Act will regulate intermediaries dealing with certain cryptocurrencies, with a particular focus on consumer protection and anti-money laundering. It will also provide a stable regulatory licensing and operating framework for cryptocurrency entities, effectively covering all crypto businesses and exchanges based in Singapore. According to PWC 82% of the surveyed executives in Singapore reported blockchain initiatives underway and 13% of them have already brought the initiatives live to the market. There is also an increasing list of organizations that are starting to provide digital payment services. Moreover, Singaporean blockchain developers Building Cities Beyond has recently created an innovation $15 million grant to encourage development on its ecosystem. This all suggests that Singapore tries to position itself as (one of) the leading blockchain hubs in the world.
 
Zilliqa seems to already take advantage of this and recently helped launch Hg Exchange on their platform, together with financial institutions PhillipCapital, PrimePartners and Fundnel. Hg Exchange, which is now approved by the Monetary Authority of Singapore (MAS), uses smart contracts to represent digital assets. Through Hg Exchange financial institutions worldwide can use Zilliqa's safe-by-design smart contracts to enable the trading of private equities. For example, think of companies such as Grab, Airbnb, SpaceX that are not available for public trading right now. Hg Exchange will allow investors to buy shares of private companies & unicorns and capture their value before an IPO. Anquan, the main company behind Zilliqa, has also recently announced that they became a partner and shareholder in TEN31 Bank, which is a fully regulated bank allowing for tokenization of assets and is aiming to bridge the gap between conventional banking and the blockchain world. If STOs, the tokenization of assets, and equity trading will continue to increase, then Zilliqa’s public blockchain would be the ideal candidate due to its strategic positioning, partnerships, regulatory compliance and the technology that is being built on top of it.
 
What is also very encouraging is their focus on banking the un(der)banked. They are launching a stablecoin basket starting with XSGD. As many of you know, stablecoins are currently mostly used for trading. However, Zilliqa is actively trying to broaden the use case of stablecoins. I recommend everybody to read this text that Amrit Kumar wrote (one of the co-founders). These stablecoins will be integrated in the traditional markets and bridge the gap between the crypto world and the traditional world. This could potentially revolutionize and legitimise the crypto space if retailers and companies will for example start to use stablecoins for payments or remittances, instead of it solely being used for trading.
 
Zilliqa also released their DeFi strategic roadmap (dating November 2019) which seems to be aligning well with their OpFi strategy. A non-custodial DEX is coming to Zilliqa made by Switcheo which allows cross-chain trading (atomic swaps) between ETH, EOS and ZIL based tokens. They also signed a Memorandum of Understanding for a (soon to be announced) USD stablecoin. And as Zilliqa is all about regulations and being compliant, I’m speculating on it to be a regulated USD stablecoin. Furthermore, XSGD is already created and visible on block explorer and XIDR (Indonesian Stablecoin) is also coming soon via StraitsX. Here also an overview of the Tech Stack for Financial Applications from September 2019. Further quoting Amrit Kumar on this:
 
There are two basic building blocks in DeFi/OpFi though: 1) stablecoins as you need a non-volatile currency to get access to this market and 2) a dex to be able to trade all these financial assets. The rest are built on top of these blocks.
 
So far, together with our partners and community, we have worked on developing these building blocks with XSGD as a stablecoin. We are working on bringing a USD-backed stablecoin as well. We will soon have a decentralised exchange developed by Switcheo. And with HGX going live, we are also venturing into the tokenization space. More to come in the future.”
 
Additionally, they also have this ZILHive initiative that injects capital into projects. There have been already 6 waves of various teams working on infrastructure, innovation and research, and they are not from ASEAN or Singapore only but global: see Grantees breakdown by country. Over 60 project teams from over 20 countries have contributed to Zilliqa's ecosystem. This includes individuals and teams developing wallets, explorers, developer toolkits, smart contract testing frameworks, dapps, etc. As some of you may know, Unstoppable Domains (UD) blew up when they launched on Zilliqa. UD aims to replace cryptocurrency addresses with a human-readable name and allows for uncensorable websites. Zilliqa will probably be the only one able to handle all these transactions onchain due to ability to scale and its resulting low fees which is why the UD team launched this on Zilliqa in the first place. Furthermore, Zilliqa also has a strong emphasis on security, compliance, and privacy, which is why they partnered with companies like Elliptic, ChainSecurity (part of PwC Switzerland), and Incognito. Their sister company Aqilliz (Zilliqa spelled backwards) focuses on revolutionizing the digital advertising space and is doing interesting things like using Zilliqa to track outdoor digital ads with companies like Foodpanda.
 
Zilliqa is listed on nearly all major exchanges, having several different fiat-gateways and recently have been added to Binance’s margin trading and futures trading with really good volume. They also have a very impressive team with good credentials and experience. They don't just have “tech people”. They have a mix of tech people, business people, marketeers, scientists, and more. Naturally, it's good to have a mix of people with different skill sets if you work in the crypto space.
 
Marketing & Community
 
Zilliqa has a very strong community. If you just follow their Twitter their engagement is much higher for a coin that has approximately 80k followers. They also have been ‘coin of the day’ by LunarCrush many times. LunarCrush tracks real-time cryptocurrency value and social data. According to their data, it seems Zilliqa has a more fundamental and deeper understanding of marketing and community engagement than almost all other coins. While almost all coins have been a bit frozen in the last months, Zilliqa seems to be on its own bull run. It was somewhere in the 100s a few months ago and is currently ranked #46 on CoinGecko. Their official Telegram also has over 20k people and is very active, and their community channel which is over 7k now is more active and larger than many other official channels. Their local communities also seem to be growing.
 
Moreover, their community started ‘Zillacracy’ together with the Zilliqa core team ( see www.zillacracy.com ). It’s a community-run initiative where people from all over the world are now helping with marketing and development on Zilliqa. Since its launch in February 2020 they have been doing a lot and will also run their own non-custodial seed node for staking. This seed node will also allow them to start generating revenue for them to become a self sustaining entity that could potentially scale up to become a decentralized company working in parallel with the Zilliqa core team. Comparing it to all the other smart contract platforms (e.g. Cardano, EOS, Tezos etc.) they don't seem to have started a similar initiative (correct me if I’m wrong though). This suggests in my opinion that these other smart contract platforms do not fully understand how to utilize the ‘power of the community’. This is something you cannot ‘buy with money’ and gives many projects in the space a disadvantage.
 
Zilliqa also released two social products called SocialPay and Zeeves. SocialPay allows users to earn ZILs while tweeting with a specific hashtag. They have recently used it in partnership with the Singapore Red Cross for a marketing campaign after their initial pilot program. It seems like a very valuable social product with a good use case. I can see a lot of traditional companies entering the space through this product, which they seem to suggest will happen. Tokenizing hashtags with smart contracts to get network effect is a very smart and innovative idea.
 
Regarding Zeeves, this is a tipping bot for Telegram. They already have 1000s of signups and they plan to keep upgrading it for more and more people to use it (e.g. they recently have added a quiz features). They also use it during AMAs to reward people in real-time. It’s a very smart approach to grow their communities and get familiar with ZIL. I can see this becoming very big on Telegram. This tool suggests, again, that the Zilliqa team has a deeper understanding of what the crypto space and community needs and is good at finding the right innovative tools to grow and scale.
 
To be honest, I haven’t covered everything (i’m also reaching the character limited haha). So many updates happening lately that it's hard to keep up, such as the International Monetary Fund mentioning Zilliqa in their report, custodial and non-custodial Staking, Binance Margin, Futures, Widget, entering the Indian market, and more. The Head of Marketing Colin Miles has also released this as an overview of what is coming next. And last but not least, Vitalik Buterin has been mentioning Zilliqa lately acknowledging Zilliqa and mentioning that both projects have a lot of room to grow. There is much more info of course and a good part of it has been served to you on a silver platter. I invite you to continue researching by yourself :-) And if you have any comments or questions please post here!
submitted by haveyouheardaboutit to CryptoCurrency [link] [comments]

On Partition Tolerance

Suppose some disaster brings down the global internet for a few weeks or months. Several City-sized networks remain in operation, each with a stake pool or two.
I would imagine that if you're in a city with a functioning network, then you can continue using Cardano. Later, when connectivity is restored, what happens?
My fear is that whichever history goes with the city that has the most Cardano wins, which would make sense from a proof of stake perspective... Just like how Bitcoin resolves forks, but with stake instead of hash power.
It seems possible though, that the histories could be merged (or rebased?) If each only contains transactions from people in that city. Your Cardano network identity could only double spend if your private key was in two cities at the same time during the downtime--a condition that could be detected and require resolution before the merge could continue.
So that's how I would design it, but I'm hoping somebody point me in the right direction to know how it actually works.
submitted by __MatrixMan__ to cardano [link] [comments]

the year 2020 in Bitcoin Cash so far: a detailed history

the year 2020 in Bitcoin Cash so far: a detailed history
What follows at the bottom is a four page long chronological overview of what happened in BCH in 2020 so far. To make it more digestable and fun to read I start with my narrating of the story.
My attempt was to remain as objective as possible and "let the facts speak for themselve" with everything sourced. I also link to many read.cash articles, the decision of which are the important ones to include is certainly not easy, I count on the rest of the community if I overlooked anything important.

summary & my narrating of the story:
The year started out relatively calm, with cashfusion in "the news" and an older ongoing controversy between Amaury and Roger Ver being worked out. Starting Jan 22nd all debate broke loose with the announcement of “Infrastructure Funding Plan for Bitcoin Cash” by Jiang Zhuoer of BTC.TOP. To illustrate this point 2 days later coinspice ran the title " Roger Ver Praises Vigorous Debate, [...]" and 6 days, less than a week, later Chris Pacia made a read.cash post titled "The 253rd "Thoughts on developer funding" Article" which might have been only a slight exaggeration or he might have been counting. Part of the reason of the tsunami was the lack of worked out details. By the time of Pacia's post a lot had changed: Both BU, Bitcoin Verde and a group of miners had made announcements not to go along with "the plan".
On feb 1st, the second version of the IFP was announced by Jiang Zhuoer in a post “BCH miner donation plan update”. Two weeks later on Feb 15th, the third iteration was announced by Bitcoin ABC which was to be activated by hashrate voting and on the same day Flipstarter was introduced, a sign of the search for alternative solutions. After a few more days and a few more people coming out more against the IFP (including Jonald Fyookball, Mark Lundeberg & Josh Ellithorpe), BCHN was announced on feb 20th with a formal release a week later. Also feb 27th, the DAA was brought back into the conversation by Jonathan Toomim with his " The BCH difficulty adjustment algorithm is broken. Here's how to fix it." video. By early march the IFP was effectively dead with its author Jiang Zhuoer vowing to vote against it. This became clear to everyone when ABC, a day later sudddenly shifted gears towards non-protocol, donation based funding: the IFP was dead. End march ABCs 2020 Business Plan was announced as a way to raise $3.3 million. Mid april to mid may was the high time for voluntary funding with four node implementations and General Protocols, a BCH DeFi Startup successfully raising funds.
By May 15th, the 6th HF network upgrade things had pretty much cooled down. The upgraded included nothing controversial and even saw an unexpected doubling in the unconfirmed transaction chain. June 15th a month later things started to heat up again with the BCHN announcement to remove the "poison pill" or "automatic replay protection". 8th Jul Jonathan Toomim posted "BCH protocol upgrade proposal: Use ASERT as the new DAA" which promised the solution to the long dragging DAA problem. Jul 23th however an unexpected twist occurred when Amaury Séchet posted "Announcing the Grasberg DAA" an incompatible, alternative solution. This, again, sparked a ton of debate and discussion. Grasberg lasted just two weeks from Jul 23th to Aug 6th when ABC announced its plans for the november 2020 upgrade but it had successfully united the opposition in the meanwhile. ABCs plan for november included dropping grasberg in favour of aserti3–2d and introducing IFPv4. Now we're here August 8th, the IFP which was declared dead after just over a month (Jan 22-Mar 5) is now back in full force. The rest of the history is still being written but if p2p electronic cash is to succeed in any big regard it's very thinkable that these events will get into history books.

Important resources: coinspice IFP timeline & Compiled list of BCH Miner Dev Fund posts, articles, discussions

History
Jan 13th : “Do CoinJoins Really Require Equal Transaction Amounts for Privacy? Part One: CashFusion” article by BitcoinMagazine [source]
Jan 13th : “Clearing the Way for Cooperation” Read.cash article by Amaury Séchet [source] on the controversy with Roger Ver about the amount of donations over the years
Jan 22nd : “Infrastructure Funding Plan for Bitcoin Cash” IFPv1 announced by Jiang Zhuoer of BTC.TOP [source] IFPv1: 12.5% of BCH coinbase rewards which will last for 6 months through a Hong Kong-based corporation & to be activated on May 15th
Jan 22nd : ”Bitcoin Cash Developers React to Infrastructure Fund Announcement: Cautiously Optimistic” coinspice article including Amaury Séchet, Antony Zegers, Jonald Fyookball & Josh Ellithorpe [source]
Jan 23rd : Jiang Zhuoer reddit AMA [source] [coinspice article]
Jan 23rd : Vitalik weighs in with his take on twitter [source]
Jan 23rd :” On the infrastructure funding plan for Bitcoin Cash” article by Amaury Séchet [source] [coinspice article] in which he proposed to place control of the IFP key in his hands together with Jonald Fyookball and Antony Zegers. . A group of 7 to 12 miners, developers, and businessmen in total would get an advisory function.
Jan 24th : “Bitcoin.com's Clarifications on the Miner Development Fund“ which emphasizes, among other things, the temporary and reversible nature of the proposal [source] [coinspice article]
Jan 24th : “Little Known (But Important!) Facts About the Mining Plan” Read.cash article by Jonald Fyookball in which he defended the IFP and stressed its necessity and temporary nature.
Jan 25th : massive amounts of public debate as documented by coinspice [coinspice article] with Justin Bons, Tobias Ruck and Antony Zegers explaining their take on it.
Jan 26th : public debate continues: “Assessment and proposal re: the Bitcoin Cash infrastructure funding situation” Read.cash article by imaginary_username [source] which was noteworthy in part because the post earned over Earns $1,000+ in BCH [coinspice article] and “The Best Of Intentions: The Dev Tax Is Intended to Benefit Investors But Will Corrupt Us Instead” by Peter Rizun [source]
Jan 27th : “We are a group of miners opposing the BTC.TOP proposal, here's why” article on Read.cash [source] [reddit announcement]
Jan 27th : Bitcoin Unlimited's BUIP 143: Refuse the Coinbase Tax [source][reddit announcement]
Jan 28th : “Bitcoin Verde's Response to the Miner Sponsored Development Fund” read.cash article by Josh Green in which he explains “Bitcoin Verde will not be implementing any node validation that enforces new coinbase rules.” [source]
Jan 28th : “Update on Developer Funding” read.cash article from Bitcoin.com [source] in which they state “As it stands now, Bitcoin.com will not go through with supporting any plan unless there is more agreement in the ecosystem such that the risk of a chain split is negligible.” And that “any funding proposal must be temporary and reversible.” This announcement from bitcoin.com and their mining pool lead the anonymous opposition miners to stand down. [source]
Jan 28th : The 253rd "Thoughts on developer funding" Article – by Chris Pacia, to tackle the “serious misconceptions in the community about how software development works”. He ends on a note of support for the IFP because of lack of realistic alternatives. [source]
Feb 1st: “BCH miner donation plan update” IFPv2 announced by Jiang Zhuoer of BTC.TOP [source] Which changes the donation mechanism so miners directly send part of their coinbase to the projects they wants to donate to. It would be activated with hashrate voting over a 3-month period with a 2/3 in favour requirement. The proposal also introduces a pilot period and a no donation option, Jiang Zhuoer also says he regards 12.% as too much.
Feb 7th: Group of BCH miners led by AsicSeer voice scepticism about the IFP during a reddit AMA [source]
Feb 15th: “On the Miner Infrastructure Funding Plan” article by Bitcoin ABC [source] In which they announce they will implement IFPv3 in their upcoming 0.21.0 release. This version has amount reduced to 5% of block reward and will go in effect with BIP 9 hashratevoting and a whitelist with different projects.
Feb 15th : “Introducing Flipstarter” [source]
Feb 16th :” Bitcoin.com’s stance on the recent block reward diversion proposals” video by Roger Ver on the Bitcoin.com Official Channel. [source] > Ver called Zhuoer’s IFP “clever” but ultimately “problematic.” [coinspice article]
Feb 16th :” BCH miner donation plan update again” read.cash article by Jiang Zhuoer of BTC.TOP [source] In which he briefly outlines the details of IFPv3
Feb 17th : “Latest Thoughts On Infrastructure Mining Plan” post by Jonald Fyookball [source]
Feb 17th : “Regarding the Bitcoin Cash Infrastructure Funding Plan, I am certain now that it should be scrapped immediately.” tweet by Mark Lundeberg [source]
Feb 19th : “Thoughts on the IFP - A Dev Perspective“ read.cash article by Josh Ellithorpe [source]
Feb 20th : “Bitcoin Cash Node” post announcing the new node implementation [source]
Feb 20th : First “Bitcoin Cash Developer Meeting” After IFP Proposal [source]
Feb 24th : “Flipstarter 500k, 6 independent campaigns” post announcing the goal to “fund the BCH ecosystem with 6 independent campaigns and an overall 500,000 USD target” [source]
Feb 27th : BCHN Formally Released [source]
Feb 27th : “The BCH difficulty adjustment algorithm is broken. Here's how to fix it.” Video by Jonathan Toomim [source]
Mar 3th :” Bitcoin Cash Node 2020: plans for May upgrade and beyond” post by BCHN [source]
Mar 4th :”Author of the Bitcoin Cash IFP [Jiang Zhuoer] Vows to Vote Against It, Using Personal Hash in Opposition” [source]
Mar 5th :Bitcoin ABC announces their 2020 Business Plan Fundraising for later in march [source]
Mar 15th : “EatBCH campaign funded! Next: node campaigns.” campaign funded after 11 hours [source]
Mar 30th : Bitcoin ABC 2020 Business Plan [source] $3.3 Million Fundraiser [source]
Apr 17th : Five flipstarter node campaign launched. [source]
Apr 26th : BCHN flipstarter campaign successfully funded. [source]
Apr 27th : VERDE flipstarter campaign successfully funded. [source]
May 4th : KNUTH flipstarter campaign successfully funded. [source]
May 7th : “BCH DeFi Startup General Protocols Raises Over $1 mil“ [source]
May 8th : BCHD flipstarter campaign successfully funded. [source]
May 9th : Deadline for node campaigns, ABC flipstarter campaign not funded. [source]
May 14th : “With IFP Defeated, Bitcoin ABC, ViaBTC & CoinEX CEO Publicly Consider a Bitcoin Cash Foundation” [source]
May 15th : deadline for ABC fundraiser campaign, ends at 55% completed. [source]
May 15th : 6th HF network upgrade -> new opcode op_Reversebytes, increased of the chained transaction limit from 25 to 50, and the improved counting of signature operations using the new “Sigchecks” implementation [source] with the “Controversial Funding Plan Rejected by Miners” [source]
May 25th : “Announcing the SLP Foundation” [source]
Jun 15st : “BCHN lead maintainer report 2020-06-15” announcement to remove the Automatic Replay Protection (a.k.a. the Poison Pill) from BCHN in november [source]
Jun 16st : “So [BCHN] is going to fork off from BCH at the next upgrade. Same old story. […]” tweeted Vin Armani [source]
Jun 21st : “Why Automatic Replay Protection Exists” post by Shammah Chancellor [source]
Jul 7th : “The Popular Stablecoin Tether Is Now Circulating on the Bitcoin Cash Network” [source]
Jul 8th : “BCH protocol upgrade proposal: Use ASERT as the new DAA” post by Jonathan Toomim [source]
Jul 18th : “$6M Worth of Tether on the Bitcoin Cash Chain Highlights the Benefits of SLP Tokens” [source]
Jul 23th : “Announcing the Grasberg DAA” post by Amaury Séchet[source]
Jul 24th : “Thoughts on Grasberg DAA” post by Mark Lundeberg [source]
Jul 29th : CashFusion security audit has been completed [source]
Jul 31st : Electron Cash 4.1.0 release with CashFusion support [source]
4th year, august 2020 – 2021
Aug 1st : “Bitcoin Cash: Scaling the Globe“ Online conference for ForkDay Celebration [source]
Aug 2nd : >“Is there going to be a fork between ABC and BCHN?” > “IMO it is very likely. If not in November, then next May.” – Amaury Séchet
Aug 3rd : “Dark secrets of the Grasberg DAA” post by Jonathan Toomim [source]
Aug 3rd : “Joint Statement On aserti3-2d Algorithm“ post by General Protocols, including Cryptophyl, Read.cash, Software Verde & SpinBCH [source]
Aug 3rd : Knuth announces they will be implementing aserti3-2d as DAA for november. [source]
Aug 3rd : Amaury rage quit from the developer call [source]
Aug 4th : “But why do people care about compensating for historical drift? Seems like a tiny problem and if it's causing this much social discord it seems not even worth bothering to try to fix.” Tweet by Vitalik [source]
Aug 5th : “Bitcoin Cash (BCH) November 2020 Upgrade statement” signed by BCHD, electron cash, VERDE, BU members, BCHN developers, Jonathan Toomim, Mark B. Lundeberg and many others [source]
Aug 5th : “BCHN FAQ on November 2020 Bitcoin Cash network upgrade” [source]
Aug 6th : “Bitcoin ABC’s plan for the November 2020 upgrade” [source] the announcement that they will drop Grasberg in favour of aserti3–2d (ASERT) and will also include FPv4 in which 8% of the blockreward goes to ABC as development funding.
Aug 7th : “Joint Statement from BCH Miners regarding Bitcoin ABC and the November 2020 BCH Upgrade.” Read.cash article by asicseer [source] stating “Over recent months, most miners and pools have switched to BCHN, and presently operate a majority of BCH hashrate.”
Aug 7th : “Simple Ledger Protocol's Joint Statement Regarding Bitcoin ABC on BCH's November 2020 Upgrade” read.cash post by the SLP-Foundation [source]
submitted by Mr-Zwets to btc [link] [comments]

What the Hash? - How Bitcoin and Blockchains use Hash ... Nicolas Courtois On Hash Rate 51 and Protection Against Double Spending In Bitcoin and Other Crypto Bitcoin - Cryptographic hash function - YouTube Probability in Bitcoin Mining: The Hashing Function Hashing - Double Hashing - YouTube

SHA256 is used as well because Bitcoin's use of a hash of a public key might create unique weaknesses due to unexpected interactions between RIPEMD and ECDSA (the public key signature algorithm). Interposing an additional and very different hash operation between RIPEMD and ECDSA makes it almost inconceivable that there might be a way to find address collisions that is significantly easier ... For double hashing, if there is a collision with the first hash function, you'd use the second hash function, but what if there is still a collision? For example, let's say a hash table is size 15 and the hash function is (key + 3) % 15 and the second hash function is ((key % 8) / 3) + 2. Let's say "insert 59" goes to index 2 by the first hash ... Output muss laut Bitcoin-Protokoll ein neuer Hash sein, bei dem die ersten 17 Bits mit Nullen belegt sind. Dieser neue Hash ist nur zu finden, indem die Miner-Rechner so lange herumprobieren und immer wieder die Nonce austauschen, bis die Aufgabe gelöst ist. Dieses ausgesprochen rechenintensive Konsensverfahren wird "Proof-of-Work" (PoW) genannt. Hash function choices. In the original 1997 algorithm hashcash used SHA1 because at that time, this was the defacto and NIST recommended hash, and the previous defacto hash MD5 had recently started to show signs of weakness. Bitcoin being specified/released in 2008/2009 uses SHA256. There is actually no strong reason SHA1 would not have worked ... Die Schwierigkeit ist ein Wert, der zeigt, wie schwer es ist, einen Hash zu finden, der niedriger ist als das vom System definierte Ziel.. Das Bitcoin-Netzwerk hat eine globale Block - Schwierigkeit. Gültige Blöcke müssen einen Hash unter diesem Ziel haben. Mining-Pools haben auch einen Pool-spezifischen Aktienschwierigkeit, eine untere Grenze für Aktien zu setzen.

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What the Hash? - How Bitcoin and Blockchains use Hash ...

Learn what a hash function does and how it is used in bitcoin and blockchains in general. Leave questions in the comments and we'll do our best to answer! On... Video 54 of a series explaining the basic concepts of Data Structures and Algorithms. This video explains the concept of Double Hashing. This video is meant ... How does a hash function work? Can you reverse a hash function? Are there risks of dependence on SHA-256? What is the purpose of double hashing to produce the address? These questions are from the ... Nicolas Courtois On Hash Rate 51 and Protection Against Double Spending In Bitcoin and Other Crypto How does the hash function work in the world of Bitcoin mining? Peter Van Valkenburgh of the Coin Center explains how the hash function in Bitcoin uses entropy to select Bitcoin miners.

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