“Segwit2x”, a proposal for an incompatible change to the consensus rules of the Bitcoin network, has received increased exposure recently. There have been attempts to mislead people into believing that the btc1 project, the implementation of the Segwit2x proposal, is a necessary update to existing software—it is not. Instead, it is a contentious deviation from the existing network rules, and its users will soon find themselves disagreeing with the rest of the network about the validity of blocks and transactions.

Please be aware that:

Segregated Witness (or Segwit, a soft fork which will be active within the coming days) is not related to the Segwit2x hard fork. Segregated Witness is backwards compatible with all previous Bitcoin software. For the vast majority of Bitcoin users, no action is required.

bitcoincore.org is the official website and @bitcoincoreorg is the official Twitter account of the Bitcoin Core project. Any other websites or Twitter accounts claiming to represent the project are fraudulent. Bitcoin Core is an open source project that welcomes contributions and review from anyone through its GitHub project. Bitcoin Core binaries can be obtained from bitcoincore.org and are always digitally signed by the release manager’s signing key. The latest version of Bitcoin Core at the time of writing is 0.14.2.

btc1 is not connected to Bitcoin Core in any way. No regular Bitcoin Core contributors support btc1 or have any connection to the project, nor were any involved in the design of its proposed hard fork.

We strongly advise users not to download any Bitcoin full-node software claiming to be an ‘upgrade’ to Bitcoin’s consensus rules without carefully considering the impact of the proposed changes on the Bitcoin system and the level of community support for it. This includes proposed consensus changes in new releases of Bitcoin Core.

While it is difficult to determine what the broader Bitcoin community supports, be wary of claims suggesting the large and diverse Bitcoin community is moving entirely to one fork or another, without independent verification. Sign-on letters have been used by companies claiming to represent their clients/users without their agreement, and have often used imprecise and misleading language. In the past, letters for Bitcoin XT, Bitcoin Classic, and Bitcoin Unlimited, as well as others, have been circulated to indicate general support of an idea, while being trumpeted as commitments to run software irrespective of community considerations, only to be dropped some months later.

Concerns raised by Bitcoin Core contributors and Bitcoin community members about the Segwit2x proposal have not been adequately addressed by its proponents. The details of the proposal were established before Bitcoin’s Segregated Witness activation, and before the recent creation of the BCH currency. It is irresponsible to ignore the outcome of these events when planning for the future. As an example, we’ve seen the confusion that arises when a single address is valid across two chains, yet the Segwit2x proposal intends to repeat the same mistake. Furthermore, BCH’s implementation of strong replay protection provided significant protection to users of both BCH, as well as Bitcoin, something Segwit2x does not plan on providing.