Future Signing with Zero-Trust dWallets

🚧 Under Construction 🚧

This SDK is still in an experimental phase. We advise you use the SDK with localnet.

Future signing allows you to create partial signatures that can be completed later without requiring immediate user interaction. This maintains zero-trust security through encryption.

Prerequisites

• An active zero-trust dWallet
• Your encrypted user share from dWallet creation
• UserShareEncryptionKeys for cryptographic operations
• A completed presign (same as regular signing)
• IKA and SUI tokens for transaction fees

Two-Phase Process

Phase 1: Create partial signature using your encrypted share

Phase 2: Complete the signature later with message approval - maintains zero-trust security

Step 1: Create Presign

First, create a presign exactly like in regular signing:

import { IkaTransaction, SignatureAlgorithm } from '@ika.xyz/sdk';
import { Transaction } from '@mysten/sui/transactions';

const tx = new Transaction();
const ikaTx = new IkaTransaction({
	ikaClient,
	transaction: tx,
	userShareEncryptionKeys,
});

const unverifiedPresignCap = ikaTx.requestPresign({
	dWallet: activedWallet,
	signatureAlgorithm: SignatureAlgorithm.ECDSA,
	ikaCoin: userIkaCoin,
	suiCoin: tx.splitCoins(tx.gas, [1000000]),
});

// Keep the presign cap for later use
tx.transferObjects([unverifiedPresignCap], [yourKeypair.toSuiAddress()]);

await signAndExecuteTransaction(tx);

Step 2: Request Future Sign

Create a partial signature for future completion:

import { Hash } from '@ika.xyz/sdk';
import { Transaction } from '@mysten/sui/transactions';

const tx = new Transaction();
const ikaTx = new IkaTransaction({
	ikaClient,
	transaction: tx,
	userShareEncryptionKeys,
});

// Verify the presign capability
const verifiedPresignCap = ikaTx.verifyPresignCap({
	presign: completedPresign,
});

// Request future sign (creates partial signature)
const unverifiedPartialUserSignatureCap = await ikaTx.requestFutureSign({
	dWallet: activedWallet,
	verifiedPresignCap,
	presign: completedPresign,
	encryptedUserSecretKeyShare: yourEncryptedUserShare,
	message: messageBytes, // Your message as Uint8Array
	hashScheme: Hash.KECCAK256,
	ikaCoin: userIkaCoin,
	suiCoin: tx.splitCoins(tx.gas, [1000000]),
});

// Keep the partial signature capability for later
tx.transferObjects([unverifiedPartialUserSignatureCap], [yourKeypair.toSuiAddress()]);

// Or deposit into your contract
tx.moveCall({
	target: '0x...',
	typeArguments: ['0x...'],
	arguments: [unverifiedPartialUserSignatureCap],
});

await signAndExecuteTransaction(tx);

Step 3: Complete Future Sign

Later, complete the signature maintaining zero-trust security:

import { Transaction } from '@mysten/sui/transactions';

const tx = new Transaction();
const ikaTx = new IkaTransaction({
	ikaClient,
	transaction: tx,
	userShareEncryptionKeys, // Required for message approval
});

// Approve the same message
const messageApproval = ikaTx.approveMessage({
	dWalletCap: activedWallet.dwallet_cap_id,
	signatureAlgorithm: SignatureAlgorithm.ECDSA,
	hashScheme: Hash.KECCAK256,
	message: messageBytes, // Must be the same message
});

// Complete the future sign
ikaTx.futureSign({
	partialUserSignatureCap: partialUserSignature.cap_id,
	messageApproval,
	ikaCoin: userIkaCoin,
	suiCoin: tx.splitCoins(tx.gas, [1000000]),
});

await signAndExecuteTransaction(tx);