Sign

This distributed signing process allows for secure transaction authorization while preserving the key's distributed nature, exemplifying the MPC wallet's enhanced security model.

Step 1 : Create Session

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• Create DuoSession if you haven't already.

Step 2 : Perform Sign

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• Call duoSession.sign() with the keyId of the keyshare to sign with. It returns a Result of Success with the Signature bytes as Data or Failure with error.

Example

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Example.swift

    let MESSAGE_HASH = "53c48e76b32d4fb862249a81f0fc95da2d3b16bf53771cc03fd512ef5d4e6ed9"

    // Sign the message hash with the key addressed by keyId (from keygen/import).
    func performSignature(keyId: String, duoSession: DuoSession) async -> Data? {
        let result = await duoSession.sign(
            keyId: keyId, message: MESSAGE_HASH,
            derivationPath: "m"  // This is the default; use your desired path, e.g. "m/1/2"
        )
        // returns nil if the operation fails, or handle it however your flow needs
        switch result {
        case .success(let signatureBytes):
            // do something with the signature bytes
            Swift.print(signatureBytes)
            return signatureBytes
        case .failure(let error):
            // show the error to the user or abort the process
            Swift.print(error)
            return nil
        }
    }

• keyId addresses the client's keyshare in your storage client (returned by keygen/import).
• messageHash is the hash of the message to be signed, passed as a hex String.
• duoSession.sign() performs message exchange between mobile and server to generate a ECDSA/EdDSA signature.
• Result of duoSession.sign() could be a Success with Data (ECDSA/EdDSA signature) of messageHash, corresponding to the public key (or address) of the wallet or Failure with error.