Author: Anthony Towns 2018-12-13 00:24:38
Published on: 2018-12-13T00:24:38+00:00
The bitcoin-dev mailing list has been discussing a combined proposal by Pieter Wuille, which includes the addition of three new sighash flags: SIGHASH_NOINPUT, SIGHASH_NOFEE, and SIGHASH_SCRIPTMASK. The new opcode OP_MASK would act as a NOP during execution. The sighash is computed like in BIP143, however, if SIGHASH_SCRIPTMASK is present, for every OP_MASK in scriptCode the subsequent opcode/push is removed. Rusty Russell raises concerns about the redundancy of having SIGHASH_SCRIPTMASK flag, as it seems to be always necessary for mask-removal when signing. Andrew Poelstra explains there are four levels of knowledge that could be had about the input when generating a signature: ALL, SINGLE, SCRIPTPUBKEY and SCRIPTMASK. In the context of a taproot world, where the alternate script is both hidden and general, the SCRIPTMASK feature allows for the preparation of a signature for one particular script in advance, even before deciding on the other scripts or building an actual transaction.
Updated on: 2023-05-20T18:04:19.794470+00:00