Account Abstraction Implementation

SSP Wallet implements ERC-4337 Account Abstraction with Schnorr signature multisignature support on EVM-compatible networks, providing advanced smart account capabilities while maintaining the security of the 2-of-2 multisignature architecture.

Overview

Account Abstraction (AA) represents a paradigm shift in how Ethereum accounts work, enabling smart contract wallets to have the same user experience as Externally Owned Accounts (EOAs) while providing additional programmable features.

SSP Wallet's implementation combines:

ERC-4337 Standard: Industry-standard Account Abstraction protocol
Schnorr Signatures: Advanced cryptographic signatures for efficiency
2-of-2 Multisignature: Maintaining SSP's core security model
Custom Validation Logic: Flexible transaction validation rules

Technical Architecture

Smart Account Structure

contract SSPSmartAccount {
    // Core validation logic
    function validateUserOp(UserOperation op, bytes32 opHash, uint256 missingAccountFunds)
        external returns (uint256 validationData);
    
    // Execute user operations
    function execute(address dest, uint256 value, bytes calldata func) external;
    
    // Batch execution
    function executeBatch(address[] calldata dest, uint256[] calldata value, bytes[] calldata func) external;
    
    // Schnorr signature validation
    function validateSchnorrSignature(bytes32 hash, bytes calldata signature) internal view returns (bool);
}

Components

1. UserOperation Structure

interface UserOperation {
  sender: string;           // Smart account address
  nonce: string;           // Nonce for replay protection
  initCode: string;        // Code to deploy account (if needed)
  callData: string;        // Transaction data
  callGasLimit: string;    // Gas limit for execution
  verificationGasLimit: string; // Gas for verification
  preVerificationGas: string;   // Gas for pre-verification
  maxFeePerGas: string;    // Maximum gas fee
  maxPriorityFeePerGas: string; // Priority fee
  paymasterAndData: string; // Paymaster info
  signature: string;        // Schnorr multisig signature
}

2. Schnorr Multisignature Validation

The smart account validates Schnorr signatures from both SSP Wallet and SSP Key:

class SchnorrMultisigValidator {
  public validateSignature(
    userOpHash: string,
    signature: string,
    publicKey1: string,
    publicKey2: string
  ): boolean {
    // Verify both signatures are valid
    const sig1Valid = this.verifySchnorrSignature(userOpHash, signature.slice(0, 64), publicKey1);
    const sig2Valid = this.verifySchnorrSignature(userOpHash, signature.slice(64, 128), publicKey2);
    
    return sig1Valid && sig2Valid;
  }
}

Key Features

1. Gasless Transactions

Users can execute transactions without holding ETH for gas fees through paymaster sponsorship:

// Example: Sponsored transaction
const userOp = await smartAccount.buildUserOperation({
  target: tokenContract,
  data: transferCalldata,
  value: 0,
  paymaster: sponsorPaymaster, // Sponsor pays gas fees
});

const signature = await sspWallet.signUserOperation(userOp);
await bundler.submitUserOperation(userOp, signature);

2. Batch Operations

Execute multiple transactions atomically in a single operation:

const batchOps = [
  {
    target: usdcContract,
    data: encodeApproval(spender, amount),
    value: 0
  },
  {
    target: dexContract,
    data: encodeSwap(tokenIn, tokenOut, amount),
    value: 0
  },
  {
    target: stakingContract,
    data: encodeStake(amount),
    value: 0
  }
];

await smartAccount.executeBatch(batchOps);

3. Session Keys

Temporary permissions for specific dApps without requiring full wallet access:

interface SessionKey {
  publicKey: string;
  validUntil: number;
  validAfter: number;
  permissions: {
    allowedTargets: string[];
    maxAmount: string;
    allowedFunctions: string[];
  };
}

// Create session key for a gaming dApp
const sessionKey = await sspWallet.createSessionKey({
  validFor: 7 * 24 * 60 * 60, // 7 days
  permissions: {
    allowedTargets: [gameContract],
    maxAmount: parseEther("0.1"),
    allowedFunctions: ["play", "claim"]
  }
});

Enhanced account recovery through trusted guardians:

interface GuardianRecovery {
  guardians: string[];
  threshold: number;
  recoveryDelay: number;
}

// Set up social recovery
await smartAccount.setupSocialRecovery({
  guardians: [guardian1, guardian2, guardian3],
  threshold: 2, // 2 out of 3 guardians needed
  recoveryDelay: 48 * 60 * 60 // 48 hours delay
});

Implementation Details

UserOperation Lifecycle

sequenceDiagram
    participant U as User
    participant W as SSP Wallet
    participant K as SSP Key
    participant B as Bundler
    participant P as Paymaster
    participant S as Smart Account
    participant BC as Blockchain
    
    U->>W: Initiate Transaction
    W->>W: Build UserOperation
    W->>P: Request Gas Sponsorship
    P->>W: Approve & Sign
    W->>K: Request Signature
    K->>K: Sign UserOperation Hash
    K->>W: Return Signature
    W->>B: Submit UserOperation
    B->>S: Validate Signature
    S->>BC: Execute Transaction
    BC->>U: Transaction Confirmed

Signature Generation Process

UserOperation Hash: Create deterministic hash of operation
Dual Signing: Both SSP Wallet and SSP Key sign the hash
Signature Aggregation: Combine signatures using Schnorr aggregation
Validation: Smart contract verifies both signatures

// Signature generation
const userOpHash = getUserOperationHash(userOp, entryPoint, chainId);

// Sign with both devices
const signature1 = await sspWallet.signHash(userOpHash);
const signature2 = await sspKey.signHash(userOpHash);

// Combine signatures
const combinedSignature = combineSchnorrSignatures(signature1, signature2);
userOp.signature = combinedSignature;

Security Enhancements

1. Multi-Layer Validation

Signature Validation: Schnorr multisignature verification
Nonce Management: Replay attack prevention
Gas Validation: Prevent gas griefing attacks
Target Validation: Whitelist of allowed contract interactions

2. Risk Management

interface RiskPolicy {
  dailySpendLimit: string;
  singleTxLimit: string;
  allowedTokens: string[];
  blockedAddresses: string[];
  timeWindows: {
    start: number;
    end: number;
  }[];
}

3. Emergency Controls

Account Freezing: Temporary suspension of operations
Recovery Mode: Fallback mechanisms for lost devices
Upgrade Protection: Secure contract upgrade procedures

Gas Optimization

1. Signature Aggregation

Schnorr signatures enable efficient aggregation, reducing gas costs:

// Optimized validation
function validateSchnorrMultisig(bytes32 hash, bytes calldata signature) 
    internal view returns (bool) {
    // Single verification call for aggregated signature
    return SchnorrVerifier.verify(hash, signature, aggregatePublicKey);
}

2. Batch Operations

Reduce individual transaction overhead through batching:

// Gas savings through batching
const individualGas = estimateGas(tx1) + estimateGas(tx2) + estimateGas(tx3);
const batchGas = estimateGas(batchTx);
const savings = individualGas - batchGas; // Typically 20-40% savings

Development SDK

Installation

npm install @runonflux/aa-schnorr-multisig-sdk

Basic Usage

import { SSPAccountAbstraction } from '@runonflux/aa-schnorr-multisig-sdk';

const aa = new SSPAccountAbstraction({
  provider: ethersProvider,
  entryPoint: ENTRY_POINT_ADDRESS,
  bundlerUrl: "https://bundler.example.com",
});

// Create smart account
const smartAccount = await aa.createAccount({
  publicKey1: sspWalletPublicKey,
  publicKey2: sspKeyPublicKey,
});

// Execute transaction
const userOp = await smartAccount.execute({
  target: tokenContract,
  data: transferCalldata,
  value: 0,
});

Advanced Configuration

const aa = new SSPAccountAbstraction({
  provider: ethersProvider,
  entryPoint: ENTRY_POINT_ADDRESS,
  bundlerUrl: "https://bundler.example.com",
  paymasterUrl: "https://paymaster.example.com",
  options: {
    gasMultiplier: 1.2, // 20% gas buffer
    maxRetries: 3,
    retryDelay: 1000,
    enableBatching: true,
    enableSessionKeys: true,
  }
});

Supported Networks

EVM Networks (Account Abstraction with ERC-4337)

Ethereum Mainnet: Full feature support (Chain ID: 1)
Polygon: Low-cost operations (Chain ID: 137)
Base: Coinbase L2 integration (Chain ID: 8453)
Binance Smart Chain: BEP-20 support (Chain ID: 56)
Avalanche: C-Chain compatibility (Chain ID: 43114)

EVM Testnets

Sepolia: Ethereum testnet (Chain ID: 11155111)
Amoy: Polygon testnet (Chain ID: 80002)

Note: Account Abstraction is only available on EVM-compatible networks. UTXO networks (Bitcoin, Litecoin, Dogecoin, etc.) use native multisignature implementations and do not support Account Abstraction features.

Under Evaluation

The following networks are being evaluated for future support:

Cardano: Multi-signature implementation research in progress
Cosmos: Inter-blockchain communication and multisig evaluation
TRON: TRC-20 and native multisig assessment
NEAR: Account model and multisig capabilities evaluation

Best Practices

1. Gas Management

Use paymasters for sponsored transactions
Batch operations when possible
Set appropriate gas limits
Monitor gas price fluctuations

2. Security Considerations

Validate paymaster trustworthiness
Implement spending limits
Regular security audits
Monitor unusual activity patterns

3. User Experience

Clear transaction previews
Progress indicators
Error handling and recovery
Educational materials

Future Roadmap

Short Term

Enhanced paymaster integration
Additional network support
Improved gas estimation
Mobile SDK optimization

Long Term

Cross-chain operations
Advanced recovery mechanisms
Institutional features
Regulatory compliance tools

SSP Wallet's Account Abstraction implementation represents a significant advancement in smart contract wallet technology, combining the security benefits of multisignature architecture with the flexibility and user experience improvements of programmable accounts.

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Last updated 5 days ago

Overview

Technical Architecture

Smart Account Structure

Components

1. UserOperation Structure

2. Schnorr Multisignature Validation

Key Features

1. Gasless Transactions

2. Batch Operations

3. Session Keys

4. Social Recovery

Implementation Details

UserOperation Lifecycle

Signature Generation Process

Security Enhancements

1. Multi-Layer Validation

2. Risk Management

3. Emergency Controls

Gas Optimization

1. Signature Aggregation

2. Batch Operations

Development SDK

Installation

Basic Usage

Advanced Configuration

Supported Networks

EVM Networks (Account Abstraction with ERC-4337)

EVM Testnets

Under Evaluation

Best Practices

1. Gas Management

2. Security Considerations

3. User Experience

Future Roadmap

Short Term

Long Term