Sign

Please refer to the Session creation section to learn how to create a new session.

Full example

ECDSA

main.dart

import 'dart:typed_data';
import 'package:silent_shard_sdk/silent_shard_sdk.dart' as sdk;

// This could be a hash digest of any message you want to sign.
// For example, for the Ethereum transaction signing, you would use the keccak256 hash of the transaction data.
const messageHash =
    'e2a159d17b7bb714aed7675d7c7d394dec8d2e4337842848104694bf89c71c03';

Future<Uint8List> signGen(sdk.EcdsaSession session) async {
  // Creating a new keyshare for demo purpose. In real application, you can use an existing keyshare.
  final sdk.DklsKeyshare keyshare = await session.keygen();
  print('Keyshare created, public key: ${keyshare.publicKeyHex}');

  final signature = await session.sign(
    keyId: keyshare.keyId,
    messageHash: messageHash,
  );

  print('Signature: $signature');

  return signature;
}

EdDSA

main.dart

import 'package:silent_shard_sdk/silent_shard_sdk.dart' as sdk;

// This could be a hash digest of any message you want to sign.
// For example, for the Ethereum transaction signing, you would use the keccak256 hash of the transaction data.
const messageHash =
    'e2a159d17b7bb714aed7675d7c7d394dec8d2e4337842848104694bf89c71c03';

Future<void> signGen(sdk.EddsaSession session) async {
  // Creating a new keyshare for demo purpose. In real application, you can use an existing keyshare.
  final sdk.SchnorrKeyshare keyshare = await session.keygen();
  print('Keyshare created, public key: ${keyshare.publicKeyHex}');

  final signature = await session.sign(
    keyId: await keyshare.keyId,
    messageHash: messageHash,
  );

  print('Signature: $signature');
}

• DklsKeyshare is the client's "share" of the MPC wallet.
• messageHash is the hash of the message to be signed as a hex string.
• When session.sign() is called, the app and the server exchange messages to generate an ECDSA signature.
• signature is the signature (hex string) of messageHash, corresponding to the public key (or address) of the wallet.