BTC Guild is NOT close to 51% of the hash share, despite previous reports here
I wanted to debunk this, not because I like BTC guild (I use Slush's pool, which thankfully is now back up), but to stop the fear mongering of BTC Guild being large and another threat besides regulation, DDoS attacks, etc. Find the service you like, use them to mine, and be done with it. The whole purpose of BTC is to have more choices and allow more market freedom. If someone chooses to use BTC guild, they probably have a reason to do so, not because tehy were forced into it. Source: http://bitcoincharts.com/bitcoin/
Making pooled mining immune to 51% attacks, selfish mining, etc. by bundling an SPV client into mining software.
This idea has been floating in my mind for a while, but I haven't seen anyone else mention it. Figured it was worth discussing.
The threat posed by pools is that they indirectly control large amounts of hashing power. Miners are mining blindly on whatever header the pool gives them, and hence can be made to attack the network at their leisure.
GetBlockTemplate was supposed to fix this problem by allowing miners to do their own transactions (and making what they're mining completely transparent). This works, but adoption is low for a few reasons:
GBT is bandwidth-hungry compared to Stratum.
GBT, to be effective. requires a miner to run a fully validating node. Most miners run very small computers as hosts for their hardware (think Raspberry PI).
Supporting GBT requires both the pool and the miner to use it (and GHash.io doesn't support it, according to the wiki).
TLDR: GBT is a great way to neuter the ability of pools to do bad things™, but it isn't widely deployed due to the resource requirements and setup effort of using it properly. Most/All the big threats posed by a large pool boil down to:
Building on a block not on top of the longest chain (51% attack/history rewriting).
Keeping the longest chain private and continuing to work on it alone (Selfish mining).
In both cases, the fact that this is occuring is actually detectable regardless of mining protocol (getwork,stratum,GBT), because the parent block hash is part of the header the miner is hashing. So the information you need to know whether you're being used to attack the network has been available all along.
By bundling an SPV client into mining software, all miners can verify that they're building on top of a block that is:
Known to the network (blocking selfish mining).
The tip of the longest chain (blocking orphaning of other blocks/51% attacks).
If this isn't the case, they can switch to their backup pool.
Advantages of the approach:
SPV is very low on resource usage, so the cost of using it is negligible. It could just be bundled into all mining software by default.
We can stop relying on "a pool would lose all its miners if it tried" and rely instead on "a pool can't get its miners to help".
Game theory wise, running such a failsafe costs nothing/nearly nothing, and it only makes you switch away from a pool when it is attacking the network, as opposed to having to switch when the pool gets too big (even if it's benign).
A pool can't tell the difference between a miner that runs this check and one that doesn't, so it can't encourage miners not to run it.
It incentivizes pools, even large ones, to get their blocks broadcast as fast as possible (so that their miners will start working on it).
Certain types of attacks against 0-conf transactions (Finney attack, Race attack) will still be possible. However, those are a risk even with 20% pools (success is at most linearly proportional to hash rate).
The best tested SPV client is built in Java (bitcoinj), so it can't be bundled into mining software easily. We'd have to find a solid implementation in C/C++ (looks like picocoin might work), or write one.
The system would have to be extremely reliable before miners are willing to use it (it shouldn't have false positives at a rate much higher than the likelyhood of attack). We could start by having it send a warning to the operator instead, and see how frequently mistakes happen.
To deal with propagation delays, the mining software would probably be willing to mine for ~30-60 seconds before triggering the failover. If blocks get so large that propagation times are close to the block interval, this will break (it will be far from the only problem they'll have).
Because SPV clients don't relay blocks, it might be possible for an evil pool to run a bunch of nodes (so that their miners connect to those), and block any IP that's not from their miners, in order to continue being able to do selfish mining. This could be addressed by verifying that multiple nodes know about the block or by getting the block from a node that knows it and relaying it to all others.
This only works against pooled mining attacks, where the hashing power belongs to people who don't want to attack the network.
If the longest chain is invalid, somehow, then miners will refuse not to build on it. This could be really bad.
Does this work, or am I missing something obvious?
To arms Bitcoin community! Help us to complete this mining installation for the Zürich MoneyMuseum. We are not asking for funds. Only your expertise needed! 20$ tip if you give us the relevant clue to solve or mitigate our main problem. Nice pictures of the exhibition inside as well…
Edit: A big thank you to all people who helped us we can now mine true pps with diff1! The people in this thread which have helped most have been awarded. I want to mention also the operator of btcmp.com denis2342 and Luke-Jr. Actually looking at the miner screen in the Linux terminal helped a lot ;-). The pool constantly resigned to stratum with variable difficulty. We can now mine true pps with diff1. Getwork with long polling seems to be default after disabling stratum... We will probably post again, when there is a video of the installation in action... Again many thanks. Learned a lot. Edit: Thank you for all the answeres so far! We will try different things now and report back. Tip bounty will be distrubuted as soon as we found out what finally does the trick. Ths could take a few days. The offerd tip will be distributed and very likeley a few others as well. First of all, let me tell you that the Bitcoin Exhibition at the Zürich MoneyMuseum is most likely the biggest and most diverse of it’s kind. Please read more about the museum and the exhibition below. Help us solve the following problem we experience with our “Muscle Powered Proof of Work” installation: Me and a friend have invested a lot of time to build an installation for the Museum. It is basically a 10GHash/s miner and RapberryPi which is powered by a hand generator (Maxon DC motor with planetary gear). Here are some pictures of the installation, although not entirely put together yet. There are still some changes planned. https://www.dropbox.com/sh/0qcvl3wu4romhnt/AAAYF08lnVAy6W6KEepE7e2Ua?dl=0 Now let’s get to the core of our problem: We are mining at the getwork diff1 pool btcmp.com as it is a true pps pool with getwork diff1. The visitors in the museum can power the generator for 2-3min and see directly how many Satoshis the "network" (actually pool but we don't want to confuse the visitors to much at that point) has given the museum for their work. This all works well so far but one problem remains. Sometimes the pool does not get a share from us for more than 40 seconds or even more than 60 in some cases. I have calculated that with 8.4 GHash/s we should find a share about every 0.5 seconds in average (diff1). I think when the pool gets a share it gets all the hashes as it then accounts for several Satoshis. Statistically we get per minute what we should get in theory. We would very much like to lower the time between the accepted shares by the pool, however. This would help to make the overall experience much smoother for the visitors. Please look at this screenshot from MinePeon and answer some questions: https://www.dropbox.com/s/lb1jei4trc9kqe5/MinePeonScreenshot.png?dl=0 We see that we get a lot of diff1 hashes. However, only 11 shares/packages have been accepted. The Is there a possibility to set the miner SW so it submits to the pool as soon as a share is found? It seems to send them in packages which sometimes have 4-5 seconds in between but sometimes a much as 80 seconds. I would like to submit packages of hashes much more often. How can this be influenced? What exactly are the Getworks (GW)? What exactly are the Accepted ones (Acc)? This is where the TipBounty is. Help us to get a better Acc/diff1 ratio. Best would be 1:1. What exactly are the rejected ones (Rej)? What exactly are the discarded ones (Disc)? What exactly are the difficulty one hashes (diff1)? Now some of these questions seem very very basic but it is important for us to understand what these are and how we can influence these. We have a 1:1 correlation between the Acc and the pool side acknowledgement of shares/packages. So whenever the MinePeon shows one more for this value the pool value for last submitted share goes to “moments ago”. Does the miner SW have a setting where we can set after how many diff1 hashes a package of hashes is sent to the pool? If no, do you have another idea why so few are sent? Ideally we would set it so the diff1 hashes are sent every 5 seconds or so, probably even more often. Is stratum with fixed diff1 possible? If so, would it be better to use stratum? Are there critical settings if we should know of? (we have tried --request-diff and --no-submit-stale) We are using BFGMiner on MinePeon if that matters. We could switch to CGMiner if that would help. Any help is very much appreciated. The museum is doing a great job explaining Bitcoin basics. We had special focus on interactive learning and have several things to underline this. I hope to hear back from you so we can improve our installation. Please don't hesitate to ask if you have further questions. We are both not mining experts. Thanks for reading and AMA. SimonBelmond Current features of the Bitcoin exhibition at the Zürich MoneyMuseum: Current Features:
Life screen with various stats/charts/parameters/transactions…
Muscle powered PoW: Hand generator with 5v and 3.5-5A output, Raspberry Pi, MinePeon, 5x Antminer U2+ plus a screen to show the hash-rate at the pool and/or in MinePeon web interface. This screen will not be hand powered. This installation will complement their coining die (go to 1:27 to see what I mean).
The Bitcoin mining evolution (CPU, GPU, FPGA, ASIC)
A few short (2-3 minutes) interviews.
Other wallets, Trezor, PiperWallet
ATM Prototype, functional
PiperWallet to use.
Casascius and other physical Bitcoins, Wallets (also some commemorative coins), Paper wallet like one out of the first Bitcoin (A)TM ever
12 Picture tours
Bitcoin for beginners
Debunking 13 Bitcoin myths
What you definitely have to know
The history of Bitcoin
Bitcoin und traditional forms of money
Alternatives to Bitcoin
Citations about Bitcoin
How do I open an account?
How do I get Bitcoin?
Bitcoin community and economy
Bitcoin as a platform
I see this as a good opportunity for Bitcoin, so let’s embrace it. I am especially excited to compare the traditional forms of money which used proof of work to the new money which also uses proof of work. I think in that context it will be much easier for the visitors to value this concept. A lot of schools and other groups book guided tours at the museum. It is open on every Friday from December 05. On. Entry is free of charge. Edit:Markdown, typos
Announcing new LTC pool! stratum, getwork, sms/mail notify, and more!
Greetings fellow miners, I've been working with Bitcoins a while now, but I got tired, so I've started with Litecoins. But none of the existing pools offered all of the services I wanted, so I decided to setup my own. Currently I'm developing the frontend to provide a better user experience. Requests for popular or usefull features can also be added on demand. The pool is quite new and the first block is not yet found, but all calculations I've done indicates that the first block will be found in one week, with only myself mining. Currently, it's a PPLNS reward system, but I'm planning to make it possible to choose between PPLNS and PPS per pool worker. I also plan to rewrite the whole frontend in the future. The url is: https://coinpool.in Features:
Mmcfe forked frontend with my modifications
Stratum + getwork (w/longpool) protocol support
International SMS & Email notifications (Free sms, with a daily limit based on donation percentage)
Server located in both Western Europe and in the US
Available on TOR and I2P
In constant development (own development environment)
Only 0.7% fee
On demand and automatic payouts
IPv6 support on getwork protocol
IRC channels are available on Freenode (#coinpool.in) and I2P (#coinpool), and I will add forum if needed. I'll hope you join me! Best regards, Meeh https://coinpool.in
Why isn't GHash/CEX.io addressing the community? BTC Guild used mitigation efforts in the past when they breached thresholds - GHash/CEX promised the same but then failed to follow through. Why haven't they explained why or made any comment?
The community has long expressed it's concern over any pool owning more then 50% of the mining network What's going on? Yesterday GHash/CEX.io's mining pool breached 51% of the hashing power in the bitcoin transaction network. This is dangerous because when a pool begins to regularly be above certain hashing power thresholds, there are weaknesses in the bitcoin transaction network that can be exploited. In a rising value currency, such weaknesses are flat out not acceptable. These security flaws become exposed when the risk of a 51% attack is exposed. How have other pools handled this in the past? In 2013, BTC Guild issued mitigation guidlines incase their pool began to breach certain thresholds of the mining network. bitcointalk link
If Pool Speed is Over 40% of Network BTC Guild will begin limiting the creation of new accounts. Additionally, the fee on PPS will be increased from 5% to 7.5% on all new miners, and will be moved to 7.5% on old miners after the difficulty changes. PPLNS will remain at the 3% + tx fees rate initially. If Pool Speed is Over 45% of Network BTC Guild will remove all getwork based pool servers within 24 hours. This is expected to reduce the pool by about 3.5 TH/s, or roughly 15% as of this post. If Pool Speed is Over 45% of Network After Getwork is Removed PPLNS fee will be raised to 4%, and new registrations will be completely closed off until speed drops back under 40%.
What is GHash/CEX's Mitigation Plan? We don't know. They have expressed goodwill towards the community but have not given any guidelines of their plan of action.
GHash.IO does not have any intentions to execute a 51% attack, as it will do serious damage to the Bitcoin community, of which we are part of. On the contrary, our plans are to expand the bitcoin community as well as utilise the hashing power to develop a greater bitcoin economic structure. If something happened to Bitcoin as a whole it could risk our investments in physical hardware, damage those who love Bitcoin and we see no benefit from having 51% stake in mining -GHash/CEX
CCN: What has ghash.io learned from the last time this happened [gaining large percentages of the hashing power?] Jeffrey Smith: We understand that the Bitcoin community strongly reacts to GHash.IO’s percentage of the total hash rate. However, we would never do anything to harm the Bitcoin economy; we believe in it. We have invested all our effort, time and money into the development of the Bitcoin economy. We agree that mining should be decentralised, but you cannot blame GHash.IO for being the #1 mining pool. CCN: What steps were put in place to ensure something like this didn’t happen again? (stop accepting miners when you guys are at 50%?) Jeffrey Smith:
Just yesterday, they repeated the same mantra. That they are coming up with a solution very soon™. via CEX's Twitter
We are not intending to capture the 51% of the overall #Bitcoin hashrate. Working on solutions for decentralising Bitcoin mining. Stay tuned
GHash/CEX, can you please address the community's concerns? Your actions currently are making us very worried. Not talking to us is only making us more anxious and frustrated. There should have been clear guidelines beforehand, and constantly prolonging this is making things worse. tl;dr?: GHash/CEX.io made promises to not breach certain thresholds in the past. They have broke these promises and not addressed the concerns of the community
Security in the bitcoin network is based on no single person having > 50% of the hashing power. However when mining in a pool you are not providing hashes for your own generated blocks, but providing work on behalf of the pool operator. The pool operator is the one who builds the blocks the pool members seem to only provide the hashing. I don't see any evidence that the mining clients that connect to pool actually verify the blocks the pools are creating. The getwork RPC call definitely doesn't give enough for the miner to validate anything, the newer method getblocktemplate seems to give the individual transaction data but is this being fully used to validate what the pool operator is doing? Typically I also found that pool mining I don't even need to sync the blockchain so again seems little verification is happing locally. My question is basically if a pool operator went rouge and started attacking the network, would this get detected immediately? Currently no pool has > 50% however the worst case would be if a few got together a did a coordinated attack, then they easily could get > 50% of the hashing power. I imagine there is something that protects the network I am not aware of, still learning how this all works.
The getblocktemplate protocol, or GBT, is a decentralized mining protocol that was developed in 2012 by Luke-Jr as a modern successor to the dated getwork protocol. The design of GBT gives contributing pool hashers more individual control over the blocks they are contributing towards. This is seen as desirable because it distributes the network mining authority more widely, instead of simply amongst a small set of mining pool operators. Not many pools support the protocol, but there are two pools where it can be used: Bitminer and Eligius. The protocol uses a series of JSON requests to work through the mining process. First the hasher gets the basic block template to start work against. Then, unlike in a centralized mining pool configuration, the hasher individually goes through all the transactions they have verified to include in the block, building the transactions' merkle root signature to use for their block hash. The hash of all the transactions is then combined with the block template to create the block header to hash against. While hashing, a hasher can request that new transaction data be signaled to him so that he can recalculate the transaction merkle root. The origin of this protocol was in improvements forrrestv made so that P2Pool could use getmemorypool over JSON-RPC to allow decentralized miners to add transactions to their blocks. Luke-Jr expanded on that work to provide a solution for his Eligius pool, and created a solution that served as a simple compromise between centralized pools and a new system like P2Pool. Luke over time has tried to promote the broad use of GTB by standardizing the concept in BIP 22 and BIP 23, and by creating open source software to make its use easier.
So I emailed the pool and this is the reponse to me telling them they have fraudulent miners.
Hello, *! Thanks ofr the feedback. Suspicious accounts was blocked, if you'll find any more bots, please let us know. Your help is much appreciated! Best regards, team 50btc.com
Kudos to 50btc.com for taking care of the issue and if you find that your GPU is being used while your PC is idle start by looking at the task manager as regular virus programs will no detect miners yet. Malware Bytes will tag cgminer and others as PUP (Potentially unwanted programs) but this is only on a full scan. Track down the offending exe and before you delete it run a wireshark and see where it is mining too. Be safe out there.
Bitcoin Core 0.10.0 released | Wladimir | Feb 16 2015
Wladimir on Feb 16 2015: Bitcoin Core version 0.10.0 is now available from: https://bitcoin.org/bin/0.10.0/ This is a new major version release, bringing both new features and bug fixes. Please report bugs using the issue tracker at github: https://github.com/bitcoin/bitcoin/issues The whole distribution is also available as torrent: https://bitcoin.org/bin/0.10.0/bitcoin-0.10.0.torrent magnet:?xt=urn:btih:170c61fe09dafecfbb97cb4dccd32173383f4e68&dn;=0.10.0&tr;=udp%3A%2F%2Ftracker.openbittorrent.com%3A80%2Fannounce&tr;=udp%3A%2F%2Ftracker.publicbt.com%3A80%2Fannounce&tr;=udp%3A%2F%2Ftracker.ccc.de%3A80%2Fannounce&tr;=udp%3A%2F%2Ftracker.coppersurfer.tk%3A6969&tr;=udp%3A%2F%2Fopen.demonii.com%3A1337&ws;=https%3A%2F%2Fbitcoin.org%2Fbin%2F Upgrading and downgrading How to Upgrade If you are running an older version, shut it down. Wait until it has completely shut down (which might take a few minutes for older versions), then run the installer (on Windows) or just copy over /Applications/Bitcoin-Qt (on Mac) or bitcoind/bitcoin-qt (on Linux). Downgrading warning Because release 0.10.0 makes use of headers-first synchronization and parallel block download (see further), the block files and databases are not backwards-compatible with older versions of Bitcoin Core or other software:
Blocks will be stored on disk out of order (in the order they are
received, really), which makes it incompatible with some tools or other programs. Reindexing using earlier versions will also not work anymore as a result of this.
The block index database will now hold headers for which no block is
stored on disk, which earlier versions won't support. If you want to be able to downgrade smoothly, make a backup of your entire data directory. Without this your node will need start syncing (or importing from bootstrap.dat) anew afterwards. It is possible that the data from a completely synchronised 0.10 node may be usable in older versions as-is, but this is not supported and may break as soon as the older version attempts to reindex. This does not affect wallet forward or backward compatibility. Notable changes Faster synchronization Bitcoin Core now uses 'headers-first synchronization'. This means that we first ask peers for block headers (a total of 27 megabytes, as of December 2014) and validate those. In a second stage, when the headers have been discovered, we download the blocks. However, as we already know about the whole chain in advance, the blocks can be downloaded in parallel from all available peers. In practice, this means a much faster and more robust synchronization. On recent hardware with a decent network link, it can be as little as 3 hours for an initial full synchronization. You may notice a slower progress in the very first few minutes, when headers are still being fetched and verified, but it should gain speed afterwards. A few RPCs were added/updated as a result of this:
getblockchaininfo now returns the number of validated headers in addition to
the number of validated blocks.
getpeerinfo lists both the number of blocks and headers we know we have in
common with each peer. While synchronizing, the heights of the blocks that we have requested from peers (but haven't received yet) are also listed as 'inflight'.
A new RPC getchaintips lists all known branches of the block chain,
including those we only have headers for. Transaction fee changes This release automatically estimates how high a transaction fee (or how high a priority) transactions require to be confirmed quickly. The default settings will create transactions that confirm quickly; see the new 'txconfirmtarget' setting to control the tradeoff between fees and confirmation times. Fees are added by default unless the 'sendfreetransactions' setting is enabled. Prior releases used hard-coded fees (and priorities), and would sometimes create transactions that took a very long time to confirm. Statistics used to estimate fees and priorities are saved in the data directory in the fee_estimates.dat file just before program shutdown, and are read in at startup. New command line options for transaction fee changes:
-txconfirmtarget=n : create transactions that have enough fees (or priority)
so they are likely to begin confirmation within n blocks (default: 1). This setting is over-ridden by the -paytxfee option.
-sendfreetransactions : Send transactions as zero-fee transactions if possible
(default: 0) New RPC commands for fee estimation:
estimatefee nblocks : Returns approximate fee-per-1,000-bytes needed for
a transaction to begin confirmation within nblocks. Returns -1 if not enough transactions have been observed to compute a good estimate.
estimatepriority nblocks : Returns approximate priority needed for
a zero-fee transaction to begin confirmation within nblocks. Returns -1 if not enough free transactions have been observed to compute a good estimate. RPC access control changes Subnet matching for the purpose of access control is now done by matching the binary network address, instead of with string wildcard matching. For the user this means that -rpcallowip takes a subnet specification, which can be
a single IP address (e.g. 220.127.116.11 or fe80::0012:3456:789a:bcde)
a network/CIDR (e.g. 18.104.22.168/24 or fe80::0000/64)
a network/netmask (e.g. 22.214.171.124/255.255.255.0 or fe80::0012:3456:789a:bcde/ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff)
An arbitrary number of -rpcallow arguments can be given. An incoming connection will be accepted if its origin address matches one of them. For example: | 0.9.x and before | 0.10.x | |--------------------------------------------|---------------------------------------| | -rpcallowip=192.168.1.1 | -rpcallowip=192.168.1.1 (unchanged) | | -rpcallowip=192.168.1.* | -rpcallowip=192.168.1.0/24 | | -rpcallowip=192.168.* | -rpcallowip=192.168.0.0/16 | | -rpcallowip=* (dangerous!) | -rpcallowip=::/0 (still dangerous!) | Using wildcards will result in the rule being rejected with the following error in debug.log:
Error: Invalid -rpcallowip subnet specification: *. Valid are a single IP (e.g. 126.96.36.199), a network/netmask (e.g. 188.8.131.52/255.255.255.0) or a network/CIDR (e.g. 184.108.40.206/24).
REST interface A new HTTP API is exposed when running with the -rest flag, which allows unauthenticated access to public node data. It is served on the same port as RPC, but does not need a password, and uses plain HTTP instead of JSON-RPC. Assuming a local RPC server running on port 8332, it is possible to request:
In every case, EXT can be bin (for raw binary data), hex (for hex-encoded binary) or json. For more details, see the doc/REST-interface.md document in the repository. RPC Server "Warm-Up" Mode The RPC server is started earlier now, before most of the expensive intialisations like loading the block index. It is available now almost immediately after starting the process. However, until all initialisations are done, it always returns an immediate error with code -28 to all calls. This new behaviour can be useful for clients to know that a server is already started and will be available soon (for instance, so that they do not have to start it themselves). Improved signing security For 0.10 the security of signing against unusual attacks has been improved by making the signatures constant time and deterministic. This change is a result of switching signing to use libsecp256k1 instead of OpenSSL. Libsecp256k1 is a cryptographic library optimized for the curve Bitcoin uses which was created by Bitcoin Core developer Pieter Wuille. There exist attacks against most ECC implementations where an attacker on shared virtual machine hardware could extract a private key if they could cause a target to sign using the same key hundreds of times. While using shared hosts and reusing keys are inadvisable for other reasons, it's a better practice to avoid the exposure. OpenSSL has code in their source repository for derandomization and reduction in timing leaks that we've eagerly wanted to use for a long time, but this functionality has still not made its way into a released version of OpenSSL. Libsecp256k1 achieves significantly stronger protection: As far as we're aware this is the only deployed implementation of constant time signing for the curve Bitcoin uses and we have reason to believe that libsecp256k1 is better tested and more thoroughly reviewed than the implementation in OpenSSL.  https://eprint.iacr.org/2014/161.pdf Watch-only wallet support The wallet can now track transactions to and from wallets for which you know all addresses (or scripts), even without the private keys. This can be used to track payments without needing the private keys online on a possibly vulnerable system. In addition, it can help for (manual) construction of multisig transactions where you are only one of the signers. One new RPC, importaddress, is added which functions similarly to importprivkey, but instead takes an address or script (in hexadecimal) as argument. After using it, outputs credited to this address or script are considered to be received, and transactions consuming these outputs will be considered to be sent. The following RPCs have optional support for watch-only: getbalance, listreceivedbyaddress, listreceivedbyaccount, listtransactions, listaccounts, listsinceblock, gettransaction. See the RPC documentation for those methods for more information. Compared to using getrawtransaction, this mechanism does not require -txindex, scales better, integrates better with the wallet, and is compatible with future block chain pruning functionality. It does mean that all relevant addresses need to added to the wallet before the payment, though. Consensus library Starting from 0.10.0, the Bitcoin Core distribution includes a consensus library. The purpose of this library is to make the verification functionality that is critical to Bitcoin's consensus available to other applications, e.g. to language bindings such as [python-bitcoinlib](https://pypi.python.org/pypi/python-bitcoinlib) or alternative node implementations. This library is called libbitcoinconsensus.so (or, .dll for Windows). Its interface is defined in the C header [bitcoinconsensus.h](https://github.com/bitcoin/bitcoin/blob/0.10/src/script/bitcoinconsensus.h). In its initial version the API includes two functions:
bitcoinconsensus_verify_script verifies a script. It returns whether the indicated input of the provided serialized transaction
correctly spends the passed scriptPubKey under additional constraints indicated by flags
bitcoinconsensus_version returns the API version, currently at an experimental 0
The functionality is planned to be extended to e.g. UTXO management in upcoming releases, but the interface for existing methods should remain stable. Standard script rules relaxed for P2SH addresses The IsStandard() rules have been almost completely removed for P2SH redemption scripts, allowing applications to make use of any valid script type, such as "n-of-m OR y", hash-locked oracle addresses, etc. While the Bitcoin protocol has always supported these types of script, actually using them on mainnet has been previously inconvenient as standard Bitcoin Core nodes wouldn't relay them to miners, nor would most miners include them in blocks they mined. bitcoin-tx It has been observed that many of the RPC functions offered by bitcoind are "pure functions", and operate independently of the bitcoind wallet. This included many of the RPC "raw transaction" API functions, such as createrawtransaction. bitcoin-tx is a newly introduced command line utility designed to enable easy manipulation of bitcoin transactions. A summary of its operation may be obtained via "bitcoin-tx --help" Transactions may be created or signed in a manner similar to the RPC raw tx API. Transactions may be updated, deleting inputs or outputs, or appending new inputs and outputs. Custom scripts may be easily composed using a simple text notation, borrowed from the bitcoin test suite. This tool may be used for experimenting with new transaction types, signing multi-party transactions, and many other uses. Long term, the goal is to deprecate and remove "pure function" RPC API calls, as those do not require a server round-trip to execute. Other utilities "bitcoin-key" and "bitcoin-script" have been proposed, making key and script operations easily accessible via command line. Mining and relay policy enhancements Bitcoin Core's block templates are now for version 3 blocks only, and any mining software relying on its getblocktemplate must be updated in parallel to use libblkmaker either version 0.4.2 or any version from 0.5.1 onward. If you are solo mining, this will affect you the moment you upgrade Bitcoin Core, which must be done prior to BIP66 achieving its 951/1001 status. If you are mining with the stratum mining protocol: this does not affect you. If you are mining with the getblocktemplate protocol to a pool: this will affect you at the pool operator's discretion, which must be no later than BIP66 achieving its 951/1001 status. The prioritisetransaction RPC method has been added to enable miners to manipulate the priority of transactions on an individual basis. Bitcoin Core now supports BIP 22 long polling, so mining software can be notified immediately of new templates rather than having to poll periodically. Support for BIP 23 block proposals is now available in Bitcoin Core's getblocktemplate method. This enables miners to check the basic validity of their next block before expending work on it, reducing risks of accidental hardforks or mining invalid blocks. Two new options to control mining policy:
-datacarrier=0/1 : Relay and mine "data carrier" (OP_RETURN) transactions
if this is 1.
-datacarriersize=n : Maximum size, in bytes, we consider acceptable for
"data carrier" outputs. The relay policy has changed to more properly implement the desired behavior of not relaying free (or very low fee) transactions unless they have a priority above the AllowFreeThreshold(), in which case they are relayed subject to the rate limiter. BIP 66: strict DER encoding for signatures Bitcoin Core 0.10 implements BIP 66, which introduces block version 3, and a new consensus rule, which prohibits non-DER signatures. Such transactions have been non-standard since Bitcoin v0.8.0 (released in February 2013), but were technically still permitted inside blocks. This change breaks the dependency on OpenSSL's signature parsing, and is required if implementations would want to remove all of OpenSSL from the consensus code. The same miner-voting mechanism as in BIP 34 is used: when 751 out of a sequence of 1001 blocks have version number 3 or higher, the new consensus rule becomes active for those blocks. When 951 out of a sequence of 1001 blocks have version number 3 or higher, it becomes mandatory for all blocks. Backward compatibility with current mining software is NOT provided, thus miners should read the first paragraph of "Mining and relay policy enhancements" above. 0.10.0 Change log Detailed release notes follow. This overview includes changes that affect external behavior, not code moves, refactors or string updates. RPC:
f923c07 Support IPv6 lookup in bitcoin-cli even when IPv6 only bound on localhost
b641c9c Fix addnode "onetry": Connect with OpenNetworkConnection
GUIminer returning "Verification failed, check hardware" on HD 6870. BitMinters Client is working though.
I want to use GUIminer and more specifiaclly I want to use the poclbm kernel because it allows me to set the -f 60 flag, which allows me to play games (league of legends) while mining. However GUIminer returns:
2013-11-20 14:14:40: Running command: poclbm.exe MetalPinguin.GPU:[email protected]:3333 --device=0 --platform=0 --verbose -r1 -v -w 128 -f 60 --verbose 2013-11-20 14:14:40: Listener for "GPU #1" started 2013-11-20 14:14:43: Listener for "GPU #1": 20/11/2013 14:14:43, started OpenCL miner on platform 0, device 0 (Barts) 2013-11-20 14:14:43: Listener for "GPU #1": stratum.bitcoin.cz:3333 20/11/2013 14:14:43, checking for stratum... 2013-11-20 14:14:43: Listener for "GPU #1": stratum.bitcoin.cz:3333 20/11/2013 14:14:43, no response to getwork, using as stratum 2013-11-20 14:14:43: Listener for "GPU #1": stratum.bitcoin.cz:3333 20/11/2013 14:14:43, Setting new difficulty: 3 2013-11-20 14:15:12: Listener for "GPU #1": stratum.bitcoin.cz:3333 20/11/2013 14:15:12, Verification failed, check hardware! (0:0:Barts, 4bb0be35) 2013-11-20 14:15:13: Listener for "GPU #1": stratum.bitcoin.cz:3333 20/11/2013 14:15:13, Verification failed, check hardware! (0:0:Barts, a4bfd3a7) 2013-11-20 14:15:19: Listener for "GPU #1" shutting down
I googled for a solution which said I should downgrade to CCC version 11.11, however this is not ideal since it would negatively affect my gaming experience. I also heard that BitMinter had a very easy to use client, so I decided to give that a shot. This client is indeed easy, as it immediatly worked! My work got accepted for the most part (5 stale out of 300+ proofs of work), however this is not the pool I want to mine in and the client does not allow me to set any parameters. Anyone know a solution, obviously there are miners that could work with my card (BitMinter), but I did not find them yet. I tried GUIminer, Phoenix and CGminer. PS: Please don't comment on whether mining is viable for me. I want to participate in Bitcoin mining with my gaming PC, my question is not about viability.
Digital money that’s instant, private, and free from bank fees. Download our official wallet app and start using Bitcoin today. Read news, start mining, and buy BTC or BCH. This pool also shows you the efficiency of your bitcoin miner, which is very unique feature that no other mining pools have. The pool operates on the fact that more efficient miners reduce the amount of resources used by server, and with fewer resources being wasted, the server can handle a large number of users. The pool operators also released poclbm-mod which is a modified version of ... Slush Pool is the 1st mining pool with more than 1.2M BTC mined since 2010. Explore features such as advanced payouts, monitoring and more. I'm looking for example getwork input and output of a successful block hash to verify a getwork client I've implemented. I'd also accept suggestions on better ways to verify this. I've looked at Bitcoin pool and getwork data validity. Ask Question Asked 8 years, 3 months ago. Active 4 years, 1 month ago. Viewed 1k times 2. 2. Bitcoin pools need to check data returned with getwork for validity (proper hashing result, etc.). Bitcoind that issues the initial getworks is also able to perform some data checking, but it might not be enough for pools (for example, it might not validate ...
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