Public key recovery for EC leaves in P2MR (BIP-360)

The discussion revolves around the challenges and considerations involved in migrating from the BIP32 standard to a new derivation standard that accommodates modern cryptographic schemes such as SHRINCS. The migration poses significant obstacles primarily because it demands users to adjust to fundamentally new concepts of what constitutes a "wallet." This transition is seen as nearly impossible without simplifying the adoption process, even with minimal initial barriers like those presented by P2TRv2.

Furthermore, there's an acknowledgment that while Hierarchical Deterministic (HD) wallets will remain prevalent, BIP32 itself must be replaced to integrate these new cryptographic mechanisms effectively. The proposed solution suggests maintaining the use of BIP39 seeds but calls for a fresh derivation standard that is compatible with newer schemes. This approach aims to retain some benefits of the P2TR model, such as delaying the exposure of the public key until the actual spending occurs via the key path. However, this comes at the expense of more complex batch validation processes and the necessity to handle the signature scheme as a black box. This means treating the new recoverable signature scheme similarly to traditional non-key-prefixed Schnorr signatures but with additional data appended to the message.

Overall, the migration strategy focuses on balancing the technical feasibility of adopting new cryptographic standards with the practical usability concerns of existing and new users within the cryptocurrency community. The objective is to facilitate a smoother transition without overhauling the fundamental user experience associated with wallet usage and management.