Bip32 Support

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

We support generating signatures for a BIP32 child key. Perform keygen once, and generate signatures for all BIP32 child keys!

Full example:

ECDSA

main.dart

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

const messageHash =
    'e2a159d17b7bb714aed7675d7c7d394dec8d2e4337842848104694bf89c71c03';

Future<void> keyDerivation(sdk.EcdsaSession session) async {
  // Keygen
  final sdk.DklsKeyshare keyshare = await session.keygen();
  print('Keyshare created, public key: ${keyshare.publicKeyHex}');

  final signature = await session.sign(
    keyId: keyshare.keyId,
    messageHash: messageHash,
    derivationPath:
        'm', // This is the default, use your desired path here. For e.g 'm/1/2'
  );
  print('Signature: $signature');

  final publicKey = keyshare.publicKeyHex;
  print('Public key: $publicKey');

  final derivedPublicKey = keyshare.deriveChildPublicKeyHex('m');
  print('Derived public key: $derivedPublicKey');
}

EdDSA

main.dart

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

const messageHash =
    'e2a159d17b7bb714aed7675d7c7d394dec8d2e4337842848104694bf89c71c03';

Future<void> keyDerivation(sdk.EddsaSession session) async {
  // Keygen
  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,
    derivationPath:
        'm', // This is the default, use your desired path here. For e.g 'm/1/2'
  );
  print('Signature: $signature');

  final publicKey = keyshare.publicKeyHex;
  print('Public key: $publicKey');

  final derivedPublicKey = keyshare.deriveChildPublicKeyHex('m');
  print('Derived public key: $derivedPublicKey');
}

• When session.sign() is called with a derivationPath, the signature is generated for the specified BIP32 derivation path.
• derivationPath is a string that specifies the path to the child key. It defaults to 'm' (no derivation) if not provided.