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

let MESSAGE_HASH = "cfa1ff5424d14eb60614d7ddf65a32243d26ddf7000d10007853d7336395efe4"

func deriveChildPublicKeyUsingKeyshare(
        keyshare: Data, duoSession: DuoSession
) async -> Data? {

    // performing signature example for context
    let result = await duoSession.signature(
        keyshare: keyshare, message: MESSAGE_HASH,
        chainPath: "m"  // This is the default, use your desired path here. For e.g 'm/1/2'
    )
    // returns nil if operation fails or other flow you might have
    switch result {
        case .success(let dataBytes):
        do {

            // do something with bytes, Here, let's derive child public key
            let childPublicKey = await SilentShardDuo.ECDSA
                .deriveChildPublicKey(
                    keyshare,
                    derivationPath: "m/1"
            )

            return dataBytes
        }
        case .failure(let error):
        do {
            // show error to user or abort process
            Swift.print(error)
            return nil
        }
    }
}

EdDSA

Example.swift

let MESSAGE_HASH = "cfa1ff5424d14eb60614d7ddf65a32243d26ddf7000d10007853d7336395efe4"

func deriveChildPublicKeyUsingKeyshare(
        keyshare: Data, duoSession: DuoSession
) async -> Data? {

    // performing signature example for context
    let result = await duoSession.signature(
        keyshare: keyshare, message: MESSAGE_HASH,
        chainPath: "m"  // This is the default, use your desired path here. For e.g 'm/1/2'
    )
    // returns nil if operation fails or other flow you might have
    switch result {
        case .success(let dataBytes):
        do {

            // do something with bytes, Here, let's derive child public key
            let childPublicKey = await SilentShardDuo.EdDSA
                .deriveChildPublicKey(
                    keyshare,
                    derivationPath: "m/1"
            )

            return dataBytes
        }
        case .failure(let error):
        do {
            // show error to user or abort process
            Swift.print(error)
            return nil
        }
    }
}

• When duoSession.signature() 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.