Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks
Isn't a faster blockchain for transactions (maybe as a sidechain) solving the problem? If there would be a safe way for 0-confirmation transactions, the Bitcoin blockchain wouldn't even be needed. On Wed, Apr 23, 2014 at 10:37 PM, Mike Hearn m...@plan99.net wrote: On Wed, Apr 23, 2014 at 10:24 PM, Gregory Maxwell gmaxw...@gmail.comwrote: Right, this works in the Bitcoin network today absent any collusion by the miners. You give one miner a transaction and you give every other node you can reach another transaction. Yes, but that can be fixed with double spend alerts. Someone you ask to not double spend is an entirely separate matter. They aren't self-selecting: you select who you trust to not make double spends and there is no need for this trust to be globally consistent. No? It's not just your decision that matters, the receiver also has to trust them. They're like a dispute mediator in this regard. You can pick whoever you want, but that doesn't matter if the receiver doesn't recognise them or trust them. You have to find an overlap to make an instant trade. In practice if people have to think about this, evaluate brands etc then you'd get a very small number of parties because the value of global agreement is so high. Then it becomes hard to remove ones that have a lot of momentum. The censorship resistance of the block chain doesn't matter if your double spending partners refuse to help you spend your money (because they're being coerced). The censorship can just happen at a different place. To stop GHash.io we would have to take away their hardware or change the Bitcoin protocol to make their hardware useless . or, have a majority decide to zero out their coinbase rewards for blocks that double spent against dice sites. That wouldn't undo the double spend, but you can't do that with the multisig scheme either. All you can do is punish the corrupted party post-hoc, either by not using them again, or by unpaying them for the service they did not provide. -- Start Your Social Network Today - Download eXo Platform Build your Enterprise Intranet with eXo Platform Software Java Based Open Source Intranet - Social, Extensible, Cloud Ready Get Started Now And Turn Your Intranet Into A Collaboration Platform http://p.sf.net/sfu/ExoPlatform ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development -- Start Your Social Network Today - Download eXo Platform Build your Enterprise Intranet with eXo Platform Software Java Based Open Source Intranet - Social, Extensible, Cloud Ready Get Started Now And Turn Your Intranet Into A Collaboration Platform http://p.sf.net/sfu/ExoPlatform___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Integration testing for BitCoin
Hey guys, it sounds great. I read through the bitcoinj documentation and started reading the code. A few years ago it wasn't a full client, but now that I see that it's almost there, it looks much more interesting :-) Testing the reorg looks critical. Thanks for the help everyone, Adam On Sat, Apr 6, 2013 at 7:21 AM, Mike Hearn m...@plan99.net wrote: In bitcoinj we desperately need integration tests to exercise the wallet code, and I think if it was done well the tests would be applicable to bitcoind as well. There have been a series of bugs in bitcoinj that boiled down to the unit tests were not realistic enough, either because they stopped simulating too early or they weren't combining multiple different things together in the same ways as happens on the real network. Sometimes timing was an issue too. Examples of what I mean - ensure that re-orgs are handled correctly and update the wallet properly in every case, etc. Something else that would be really useful, a standalone tool that stress-tests the system. If we had a tool that randomly generated chains of transactions we might have caught the bdb lock limit bug earlier. You could write such a tool using bitcoinj easily, or the raw transaction APIs on bitcoind. On Fri, Apr 5, 2013 at 8:29 PM, Adam Ritter arit...@gmail.com wrote: Thanks guys, it sounds great. Testing the JSON-RPC is/was not the main goal, just an interface for testing. I didn't know that the bitcoinj implementation is getting close to a full implementation..it sounds interesting, as it's much easier to understand and work with. I'll look at the test cases. Thanks very much, Adam On Fri, Apr 5, 2013 at 12:42 PM, Gregory Maxwell gmaxw...@gmail.com wrote: On Fri, Apr 5, 2013 at 10:24 AM, Adam Ritter arit...@gmail.com wrote: Hey guys, I just bought some BitCoins after being lazy to do it for the last few years, but also looked at the client code and the messages that are going on this mailing list. I saw that there are quite some unit tests, but I didn't find integration test for BitCoin, and I believe that it's quite important for the future of BitCoin (making the current code more stable, testing attack scenarios, refactoring and extending code). [...] Tests that simulate multiple bitcoin users and can verify that the whole network of bitcoin clients work together to achieve the goals of Bitcoin. Also maybe [System testing](http://en.wikipedia.org/wiki/System_testing) would be a better name for the tests, but I'm not sure. I prefer to call them system tests. We use a system called blocktester that Matt Corallo wrote, https://code.google.com/r/bluemattme-bitcoinj/source/browse/core/src/test/java/com/google/bitcoin/core/FullBlockTestGenerator.java?name=fullverifr=874c5904b12d1fcec5b556429cf208f63cd4e1bc It's based on BitcoinJ and works by simulating a peer against a slightly instrumented copy of Bitcoin(d/-qt) (modified to avoid computationally expensive mining). The tests simulates many complicated network scenarios and tests the boundaries of many (hopefully all) the particular rules of the blockchain validation protocol. We can use these tests to compare different versions of the reference software to each other and to bitcoinj (or other full node implementations) as well as comparing them to our abstract understanding of what we believe the rules of the protocol to be. These tests are run as part of the automated tests on every proposed patch to the reference software. Via a robot called pulltester which comments on github requests and produces logs like this: http://jenkins.bluematt.me/pull-tester/92a129980fb9b506da6c7f876aa8adb405c88e17/. Pulltester also performs automatic code coverage measurements. Additionally, we run a public secondary test bitcoin network called 'testnet', which can be accessed by anyone by starting the reference software with testnet=1. Testnet operates the same as the production network except it allows mining low difficulty blocks to prevent it going for long times without blocks, and some of the protective relaying rules against non standard transaction types are disabled. Most of this testing work has been centered around validating the blockchain behavior because thats what has serious systemic risk. Measuring the json rpc behavior is strictly less interesting, though interesting too. -- Minimize network downtime and maximize team effectiveness. Reduce network management and security costs.Learn how to hire the most talented Cisco Certified professionals. Visit the Employer Resources Portal http://www.cisco.com/web/learning/employer_resources/index.html ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin
[Bitcoin-development] Integration testing for BitCoin
Hey guys, I just bought some BitCoins after being lazy to do it for the last few years, but also looked at the client code and the messages that are going on this mailing list. I saw that there are quite some unit tests, but I didn't find integration test for BitCoin, and I believe that it's quite important for the future of BitCoin (making the current code more stable, testing attack scenarios, refactoring and extending code). I have wrote some integration tests before at other projects, and they usually turned out useful, but I have 0 experience with the BitCoin development and codebase. I wrote a short document of what I think would be the safest way to do the testing (but not yet the tests themselves, as I don't have enough experience..I'd like to have something like testing that the wallets are empty, and after somebody mines she'll have more money..after she sends money to the other person, the other person will see it...things like this, just to get to know the code base). What do you guys think? The plan is here: https://github.com/xiphias/bitcoin/blob/master/src/test/integration/README.md Please feel free to comment/fork, I'll try to write all your replies in the document as well. Also here's the text to make it easier to comment: Integration testing for bitcoin Tests that simulate multiple bitcoin users and can verify that the whole network of bitcoin clients work together to achieve the goals of Bitcoin. Also maybe [System testing](http://en.wikipedia.org/wiki/System_testing) would be a better name for the tests, but I'm not sure. Goals - - Make the bitcoin code easier to refactor while increasing the guarantee that it doesn't break the overall behaviour of the client. - Make it easier to have multiple experimental coins (for example LightCoin or PPCoin) in the codebase, while guaranteeing that the original BitCoin protocol doesn't break - Make it easy to test attack scenarios (like DOS, releasing an incompatible BitCoin client), monitoring - Have tests without (or at least minimal number of) unreadable constants and unreadable fake data to make them easier to verify. Proposed implementation The first implementation should use the JSON-RPC interface and build up as much verification of BitCoin network as possible. It should be in C++, which makes it easier to move to the second implementation. The JSON-RPC calls should be hidden by a C++ interface. The second implementation should use the same interface that was used for JSON-RPC, but using the BitCoin code directly (while not breaking the JSON-RPC tests). For this the BitCoin client has to be refactored as a library, getting rid of all global variables (and having them in a data structure), so that multiple BitCoin clients can be run in the same process. The improvement of the second implementation should have dependency injection for the time and for finding/verifying a mined block, so that the tests don't need to use real CPU power for mining, and they can run faster and test more complex scenarios. -- Minimize network downtime and maximize team effectiveness. Reduce network management and security costs.Learn how to hire the most talented Cisco Certified professionals. Visit the Employer Resources Portal http://www.cisco.com/web/learning/employer_resources/index.html ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
