Author: ZmnSCPxj 2019-10-01 15:42:08
Published on: 2019-10-01T15:42:08+00:00
In a Bitcoin development mailing list, ZmnSCPxj proposed the creation of a new opcode, `OP_CHECKSIG_WITHOUT_INPUT`, which would ignore any `SIGHASH` flags present on a signature. In response to this proposal, another member suggested that creating a new tapscript public key type might be a more effective solution. This would involve encoding the new code in the following manner: `3301AC [CHECKSIG of public key type 0x01]` or `32B3 [CHECKSIG_WITHOUT_INPUT (replacing NOP4) of key]`. Under tapscript v0, it is possible to reuse the internal Taproot pubkey by giving `OP_1` as the public key to `OP_CHECKSIG`. The proposal suggests having a similar mechanism for copying the internal Taproot pubkey while also enabling new `SIGHASH` flags for a particular script only. This would allow update transactions to use `MuSig(A,B,C)` for signing along the "update" path, with unique "state" keys, and cooperative closes would sign using `P + h(P | MAST( OPCHECKSIG)) * G`, without revealing that it was a Decker-Russell-Osuntokun output.
Updated on: 2023-06-13T21:34:32.865164+00:00