nip44: clarify ecdh hashing

1 files changed, 1 insertions, 0 deletions

diff --git a/44.md b/44.md
index f3071ea..339d300 100644
--- a/44.md
+++ b/44.md
@@ -142,6 +142,7 @@ 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]`.
+    Some libraries, like libsecp256k1, apply sha256 on the output. The hashing is unnecessary in NIP44.
 - 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`.