MultiSig

The typescript SDK supports Sui Multi-Signature (opens in a new tab) signing via the MultiSigPublicKey class.

This class implements the same interface as the PublicKey classes used by KeyPairs, and can be used to verify signatures for PersonalMessages and TransactionBlocks using the same methods.

Creating a MultiSigPublicKey

You can create a MultiSigPublicKey by providing pairs of PublicKey and weight values, along with a threshold.

import { ED25519KeyPair } from '@mysten/sui.js/keypairs/ed25519';
 
const kp1 = new ED25519KeyPair();
const kp2 = new ED25519KeyPair();
const kp3 = new ED25519KeyPair();
 
const multiSigPublicKey = MultiSigPublicKey.fromPublicKeys({
	threshold: 2,
	publicKeys: [
		{
			publicKey: kp1.getPublicKey(),
			weight: 1,
		},
		{
			publicKey: kp2.getPublicKey(),
			weight: 1,
		},
		{
			publicKey: kp3.getPublicKey(),
			weight: 2,
		},
	],
});
 
const multisigAddress = multiSigPublicKey.getAddress();

The resulting MultiSigPublicKey will allow you to verify signatures with a combined weight of at least 2. A signature signed with only kp1 or kp2 would not be considered valid, but a signature signed with kp1 and kp2, or kp3 by itself would be valid.

Combining signatures with a MultiSigPublicKey

To sign a message or transaction for a multig address, you will need to collect signatures from the individual keypairs, and then combine them into a signature using the MultiSigPublicKey class for the address.

// This example uses the same keypairs and multiSigPublicKey from the previous example
const message = new TextEncoder().encode('hello world');
 
const signature1 = (await kp1.signPersonalMessage(message)).signature;
const signature2 = (await kp2.signPersonalMessage(message)).signature;
 
const combinedSignature = multiSigPublicKey.combinePartialSignatures([signature1, signature2]);
 
const isValid = await multiSigPublicKey.verifyPersonalMessage(message, combinedSignature);

KeyPairs