[BIP proposal] Pay to Schnorr Key Hash (P2SKH)

The discussion revolves around the proposal to split r-value and s-value on the stack for signature processing in Bitcoin's scripting system. This method draws inspiration from DER signatures, aiming to make the signature smaller by grinding. By pushing the r-value and s-value separately onto the stack, and optionally including the sighash as a third element if it's not default, the process could enhance efficiency. This approach would allow easy identification of whether two or three elements have been pushed onto the stack based on their size.

Additionally, this separation of values could simplify the implementation of an operation similar to OP_CHECKSIGFROMSTACK without needing new opcodes or employing complex methods like OP_CAT. It suggests that handling the r-value independently could offer a more straightforward way to verify signatures against arbitrary messages. This conversation underscores a technical exploration within the Bitcoin Development Mailing List aimed at refining cryptographic operations and potentially optimizing script execution by leveraging the distinct handling of signature components.