BIP-110 Fork Coins Pose Replay Attack Risk on Bitcoin
A potential minority chain fork is looming for Bitcoin this weekend, but it's not just price volatility that users should be concerned about. Selling BIP-110 fork coins could inadvertently trigger replay attacks on the original Bitcoin chain, resulting in permanent loss of real BTC.
The problem arises because the new chain does not inherit Bitcoin's transaction format with any mechanism to distinguish new chain operations from legacy ones. This means a signed transaction broadcast on the fork network to sell or move new coins can be captured and replayed on Bitcoin itself.
Replay attacks are not new, as seen in the 2017 Bitcoin Cash split. The core issue is that if two chains share an identical transaction history, a valid signature on one chain remains valid on the other unless the transaction data is modified to include a chain-specific identifier.
Exchanges face a delicate operational challenge in deciding whether to credit customers with new tokens and enable trading. Historically, platforms like Coinbase and Binance have taken a cautious stance with unprotected forks, often delaying support until replay safeguards are in place.