public (byte[], byte[], byte[]) GetSignature(TxTemplate transaction, string serializedTransaction, int index, string privKey) { var pubKeyBuffer = Encoders.Base58.DecodeData(transaction.Outputs[index].PublicKeys[0]); string transactionUniqueFulfillment = GetUniqueFulfillment(transaction, serializedTransaction, index); var transactionHash = HashingUtils.ComputeSha3Hash(Encoding.UTF8.GetBytes(transactionUniqueFulfillment)); var signature = CryptographyUtility.Ed25519Sign(transactionHash, Encoders.Base58.DecodeData(privKey)); return(transactionHash, pubKeyBuffer, signature); }