Hi All, In October I sent the MuSig2 descriptor and PSBT field BIPs to the list. Since then, I've made a few changes to the BIPs and am looking for feedback on these.
The most significant change is the addition of third BIP which describes how the synthetic xpubs are constructed and derived. This is split from the descriptors BIP as I felt that the PSBT fields BIP needed to reference this process too, and referencing the descriptors BIP for that seemed a bit odd. Otherwise, the descriptors BIP is unchanged, although I am open to Salvatore's suggestion of dropping the ranged derivation within the expression and only allow ranged derivation of the aggregate pubkey itself. I've also made a change to the PSBT fields BIP where the aggregate pubkey is included as a plain pubkey rather than as xonly. I think this change is necessary for to make discovering derived keys easier. The derivation paths for derived keys contain the fingerprint of the parent (i.e. the aggregate pubkey) and the fingerprint requires the evenness bit to be serialized. So the aggregate pubkey in the PSBT fields need to contain that evenness information in order for something looking at only the PSBT to be able to determine whether a key is derived from an aggregate pubkey also specified in the PSBT. The full text of the BIPs can be found at the following: * Derivation: https://github.com/achow101/bips/blob/musig2/bip-musig2-derivation.mediawiki * Descriptors: https://github.com/achow101/bips/blob/musig2/bip-musig2-descriptors.mediawiki * PSBT: https://github.com/achow101/bips/blob/musig2/bip-musig2-psbt.mediawiki Thanks, Ava Chow _______________________________________________ bitcoin-dev mailing list bitcoin-dev@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
