code: func GenPrivKeySecp256k1FromSecret(secret []byte) PrivKeySecp256k1 {
  	privKey32 := Sha256(secret) // Not Ripemd160 because we want 32 bytes.
  	priv, _ := secp256k1.PrivKeyFromBytes(secp256k1.S256(), privKey32)
  	privKeyBytes := [32]byte{}
  	copy(privKeyBytes[:], priv.Serialize())
  	return PrivKeySecp256k1(privKeyBytes)
  }
docs: // NOTE: secret should be the output of a KDF like bcrypt,
  // if it's derived from user input.