Signing Transactions with Multisig Accounts

Learn how to create multisignature accounts here.

Once you have created the multisignature accounts, signing a transaction involves the following steps:

1. Create the signing commitment (performed by each participant)
2. Aggregate the signing commitments to create the signing package (performed by a coordinator)
3. Create signature shares using the signing package (performed by each participant)
4. Aggregate the signature shares to create the final signed transaction (performed by a coordinator)

In the examples below, we will be signing a transaction with 2 of 2 multisig accounts.

Create the signing commitment 

Once the participants agree on the contents of a transaction and who is going to participate in signing, each participant will create a signing commitment.

The identities of the participant and the unsigned transaction are required to generate a commitment.

Tip: Make sure the unsigned transaction has a sufficient expiration time to allow for the completion of the signing process. The expiration can be set to 0 to ensure the transaction never expires.

import { multisig } from '@ironfish/rust-nodejs'

const participantIdentities = [
    "723729d1b6af022a4c5d67e126a3a797...63ec486317bd1e72b8628e6116340304",
    "72c60942feac595aa83bb0856c264dfc...af2708a2961ef6c9e15541e288dcad03"
]

const participantCommitment = multisig.createSigningCommitment( 
    participantAccount.multisigKeys.secret,
    participantAccount.multisigKeys.keyPackage,
    unsignedTransaction.hash(),
    participantIdentities,
)

Aggregate the signing commitments to create the signing package 

Once all participants have created their signing commitments, the commitments are aggregated to create the signing package.

Note: This action can be performed by any participant or the coordinator.

import { UnsignedTransaction } from '@ironfish/rust-nodejs'

const unsignedTransactionData = "01010000000000000002000000000000...9f3fb432907a84c8483586a6a565d308"

const unsignedTransaction = new UnsignedTransaction(
    Buffer.from(unsignedTransactionData, 'hex'),
)

const participantCommitments = [
    "723f415e10ec47955036105834ab7dcc...342022941ff351bd60723b9a9aa2d29a",
    "721cb9582cec837588df0b08d77d4870...abc27377671c68323af864b57b718380"
]

const signingPackage = unsignedTransaction.signingPackage(participantCommitments)

Create signature shares 

Once the signing package is created and distributed to all participants, each participant can create a signature share using their secret key and the signing package.

import { multisig } from '@ironfish/rust-nodejs'

const participantSignature = multisig.createSignatureShare(
    participantAccount.multisigKeys.secret,
    participantAccount.multisigKeys.keyPackage,
    signingPackage,
)

Aggregate the signature shares to create the signed transaction 

Once all participants have created their signature shares, the shares are aggregated to create the final signed transaction.

Note: This action can be performed by any participant or the coordinator.

import { multisig } from '@ironfish/rust-nodejs'

const participantSignatures = [
    "723f415e10ec47955036105834ab7dcc...be94dd1ae640f3fcf8bddb9478a0cb02", 
    "721cb9582cec837588df0b08d77d4870...ad47e9f3ba751c77ec7530708d1d2b07"
]

const serialized = multisig.aggregateSignatureShares(
    coordinatorAccount.multisigKeys.publicKeyPackage,
    signingPackage,
    participantSignatures,
)

const transaction = new Transaction(serialized)