This weekend Mike Hearn announced the release of a version of his BitcoinXT client which would hard fork a new altcoin referred to here as XTCoin from the Bitcoin network. Should enough blocks be mined which profess to contain a vote to trigger Hearn's XTCoin fork, the XTCoin blockchain would split from the Bitcoin Blockchain an allow blocks to be mined at a maximum size of 8 megabytes each growing exponentially to a maximum size of 8 gigabytes 20 years after XTCoin forks should XTCoin somehow manage to keep enough hashpower to continue producing new blocks over the entire span of time. As mentioned in the Hard Fork Missile Crisis XTCoin, like any other altcoin forked from Bitcoin and fraudulently misrepresenting itself as Bitcoin would come under devastating economic attack which would almost certainly render further mining on the XTCoin chain a costly money losing endeavor.

Hearn has in the past been a consistent advocate for having more Bitcoin users pushed onto less reliable SPV wallets instead of fully validating Bitcoin nodes, a move that is dangerous in an environment with substantially larger blocks and a higher orphaned block rate. The use of SPV wallets clearly and plainly increases the risk of users being duped by double spend attacks during common one to three block forks triggered by orphaned blocks, events which would likely become far more common as increasingly large block sizes and block verification times make XTCoin security measurably weaker than that of Bitcoin. The danger the XTCoin for poses is such that even the /r/Bitcoin moderators lead by Theymos have been classifying XTCoin discussion as off topic and pointedly not Bitcoin discussion.

The threshold set by Mike Hearn and Gavin Andressen for voting which would trigger the fork of XTCoin is 750 of the last 1000 blocks which would be followed by a two week delay after which XTCoin nodes would begin accepting blocksizes up to 8 megabytes. This is a threshold far under that used by the depreciated BIP process for triggering soft forks and yet the relatively uncontroversial BIP 66 proposal to enforce stricter encoding of signatures lead to multiple occasions where the longest blockchain in terms of proof of work committed was out of concordance with the BIP 66 rules.

This attempt by Mike Hearn and Gavin Andressen to break the hard consensus of Bitcoin comes at a time where the Bitcoin Foundation's efforts have increasingly been rendering fruit that has substantially reduced the relevance of the Bitcoin Core implementation from which BitcoinXT itself was forked. The foundation's reference implementation of bitcoind along with the 'stator' and 'rotor' build infrastructure has substantially improved the memory footprint and performance allowing a wider range of computing hardware to be put into service as fully verifying Bitcoin network nodes.

Further an email purporting to be from Satoshi Nakamoto was posted to the Bitcoin Core mailing list, though given Satoshi's infrequent use of cryptographic signatures and loss of the email account used when he birthed Bitcoin the message is impossible difficult¹ to authenticate. The message reads as follows:

I have been following the recent block size debates through the mailing list. I had hoped the debate would resolve and that a fork proposal would achieve widespread consensus. However with the formal release of Bitcoin XT 0.11A, this looks unlikely to happen, and so I am forced to share my concerns about this very dangerous fork.

The developers of this pretender-Bitcoin claim to be following my original vision, but nothing could be further from the truth. When I designed Bitcoin, I designed it in such a way as to make future modifications to the consensus rules difficult without near unanimous agreement. Bitcoin was designed to be protected from the influence of charismatic leaders, even if their name is Gavin Andresen, Barack Obama, or Satoshi Nakamoto. Nearly everyone has to agree on a change, and they have to do it without being forced or pressured into it. By doing a fork in this way, these developers are violating the "original vision" they claim to honour.

They use my old writings to make claims about what Bitcoin was supposed to be. However I acknowledge that a lot has changed since that time, and new knowledge has been gained that contradicts some of my early opinions. For example I didn't anticipate pooled mining and its effects on the security of the network. Making Bitcoin a competitive monetary system while also preserving its security properties is not a trivial problem, and we should take more time to come up with a robust solution. I suspect we need a better incentive for users to run nodes instead of relying solely on altruism.

If two developers can fork Bitcoin and succeed in redefining what "Bitcoin" is, in the face of widespread technical criticism and through the use of populist tactics, then I will have no choice but to declare Bitcoin a failed project. Bitcoin was meant to be both technically and socially robust. This present situation has been very disappointing to watch unfold.

Satoshi Nakamoto

Since Hearn released the XTCoin client there has not been a single block committed to the Blockchain that contains the string interpreted as a vote for the XTCoin fork. At this time it appears appetite among the mining and pool operating population for Hearn and Gavin's cabal pushing the fiat regime's agenda is not significantly existent to the point it can not be detected at all.

1. Thank you to Peter Todd for the correction  ↩