Author: Jonathan Underwood 2019-07-09 22:21:25
Published on: 2019-07-09T22:21:25+00:00
On the Bitcoin-dev mailing list, Jonathan Underwood proposed a change to the bullet list for signers to ensure that the sighash type provided is acceptable to them. He gave an attack scenario where a signer's UTXO was stolen by a hacker who changed the PSBT input's sighashtype to SIGHASH_ANYONECANPAY | SIGHASH_NONE and after the fact, changed the outputs to send to themselves and added an input they signed with SIGHASH_ALL. Andrew Chow, in response, explained that this was the original intent of the sighash field; either the sighash is acceptable to the signer and the signer signs with it or they do not sign at all. Jonathan agreed with Andrew's explanation and said he would write the amendment and make a PR.
Updated on: 2023-06-13T20:01:20.450331+00:00