diff --git a/44.md b/44.md index 78c2323a..8f781b85 100644 --- a/44.md +++ b/44.md @@ -142,6 +142,8 @@ validation rules, refer to BIP-340. The operation produces a shared point, and we encode the shared point's 32-byte x coordinate, using method `bytes(P)` from BIP340. Private and public keys must be validated as per BIP340: pubkey must be a valid, on-curve point, and private key must be a scalar in range `[1, secp256k1_order - 1]`. + NIP44 doesn't do hashing of the output: keep this in mind, because some libraries hash it using sha256. + As an example, in libsecp256k1, unhashed version is available in `secp256k1_ec_pubkey_tweak_mul` - Operators - `x[i:j]`, where `x` is a byte array and `i, j <= 0` returns a `(j - i)`-byte array with a copy of the `i`-th byte (inclusive) to the `j`-th byte (exclusive) of `x`.