Presenting a BIP for Shamir's Secret Sharing of Bitcoin private keys



Summary:

A discussion took place regarding the M-1 offset versus limiting the range to 255. The former was preferred even though it may cause confusion among developers and require additional explanation in future documentation. The reason for this preference was not entirely clear, but it was suggested that it may be better to have a field where all possible values are legitimate, or perhaps it's important that powers of 2 be represented here. The conversation then shifted towards allowing the user to select one share if they wish. Though technically unnecessary, it could simplify software/hardware support and UI design. It was agreed upon to encode M using a bias of -1 so that M up to and including 256 can be encoded in one byte. Test vectors were also updated accordingly.


Updated on: 2023-06-08T17:13:31.497326+00:00