BIP32 Support

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

Perform Derive Child Public-Key

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• Call SilentShard.ECDSA.deriveChildPublicKey() or SilentShard.EdDSA.deriveChildPublicKey() which returns Result of Success with Child Public-Key bytes as Data or Failure with error.

Example

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ECDSA

Example.swift

// deriveChildPublicKey computes a child public key locally, without any MPC round.
// It takes keyshare bytes, which you read from your own StorageClient by keyId
// (the SDK owns keyshare storage). This is a public-key-only derivation — for a
// signable child keyshare use trioSession.hardDerivation(keyId:derivationPath:).
func deriveChildPublicKey(keyshare: Data) async -> Data? {
    let result = await SilentShard.ECDSA.deriveChildPublicKey(
        keyshare,
        derivationPath: "m/1"  // your desired BIP32 path
    )
    // returns nil if the operation fails, or handle it however your flow needs
    switch result {
    case .success(let childPublicKey):
        // do something with the child public-key bytes
        Swift.print(childPublicKey)
        return childPublicKey
    case .failure(let error):
        // show the error to the user or abort the process
        Swift.print(error)
        return nil
    }
}

EdDSA

Example.swift

// deriveChildPublicKey computes a child public key locally, without any MPC round.
// It takes keyshare bytes, which you read from your own StorageClient by keyId
// (the SDK owns keyshare storage).
func deriveChildPublicKey(keyshare: Data) async -> Data? {
    let result = await SilentShard.EdDSA.deriveChildPublicKey(
        keyshare,
        derivationPath: "m/1"  // your desired BIP32 path
    )
    // returns nil if the operation fails, or handle it however your flow needs
    switch result {
    case .success(let childPublicKey):
        // do something with the child public-key bytes
        Swift.print(childPublicKey)
        return childPublicKey
    case .failure(let error):
        // show the error to the user or abort the process
        Swift.print(error)
        return nil
    }
}

• When trioSession.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.