Author: Andrew Chow 2019-07-09 20:26:45
Published on: 2019-07-09T20:26:45+00:00
On July 9th, 2019, Jonathan Underwood proposed a wording change to the Bitcoin Improvement Proposal (BIP) for the sighash field, which contains information about how a transaction should be signed. He presented an attack scenario where a hacker changes the sighashtype of a partially signed Bitcoin transaction (PSBT) to SIGHASH_ANYONECANPAY | SIGHASH_NONE and then adds inputs and outputs to send BTC to themselves. Underwood suggests adding a check for signers to ensure that the sighash type provided is acceptable to them and fail signing if it is not. If no sighash type is provided, signers should use SIGHASH_ALL but may sign with any sighash type they wish.
Updated on: 2023-05-20T20:38:30.560776+00:00