I noticed in bitcoin when using the tiny-secp256k1 library to sign the signature for a signature hash of an input; the signature is always the same.
However, the signature is always different in other ECDSA-Secp256k1 libraries. (I'm using one by nordic semiconductors.)
Do I misunderstand something? Is there a difference in the signature algorithms?
I read something about randomly and deterministically calculating the k value; should it matter if it is random or not? Or is there possibly extra encoding done after the signature hash is signed in Bitcoin Secp256k1?