Confidential ERC-3643 Token (UCEF3643)

This guide provides comprehensive instructions for testing and deploying the Confidential ERC-3643 (UCEF3643) token implementation.

UCEF Integration with ERC-3643

This implementation combines the privacy-preserving features of UCEF (Unopinionated Confidential ERC-20 Framework) with the compliance and identity verification capabilities of ERC-3643. While ERC-3643 provides robust regulatory compliance through identity verification and transfer restrictions, UCEF adds a layer of programmable confidentiality to protect sensitive financial data.

Key benefits of this integration:

• Programmable Privacy: Leverages UCEF's unopinionated approach to implement confidential balances and transactions while maintaining ERC-3643's compliance features
• Regulatory Compliance: Preserves all ERC-3643 compliance mechanisms including identity verification and transfer restrictions
• Flexible Implementation: Maintains cryptographic agnosticism while enforcing privacy using standard Solidity constructs
• Enhanced Security: Combines identity-based access controls with confidential transaction capabilities

This hybrid approach ensures that regulated entities can benefit from privacy-preserving features while maintaining full compliance with regulatory requirements.

Contract Features

The UCEF3643 token implementation includes:

• ERC-3643 compliance
• UCEF privacy
• Identity verification
• Compliance checks
• Token freezing capabilities
• Transfer restrictions
• Agent management

Private Events System

The UCEF3643 token implements a privacy-preserving event system that replaces standard ERC-20 events with private events that only authorized addresses can view.

How Private Events Work

Instead of emitting standard events like Transfer or Approval, the contract emits PrivateEvent with:

• allowedViewers: Array of addresses authorized to view the event
• eventType: Hash of the original event signature (e.g., Transfer(address,address,uint256))
• payload: ABI-encoded event arguments

Event Types Supported

• EVENT_TYPE_TRANSFER: Private transfer events
• EVENT_TYPE_APPROVAL: Private approval events
• EVENT_TYPE_TOKENS_FROZEN: Private token freezing events
• EVENT_TYPE_TOKENS_UNFROZEN: Private token unfreezing events

Authorized Viewers

Private events are only visible to:

• Affected addresses: The from and to addresses in transfers
• Auditor: The designated auditor address (if set)
• Event participants: Owners and spenders in approval events

Auditor Role

The contract includes an auditor role that can be set by agents:

function setAuditor(address _auditor) external onlyAgent

The auditor receives access to all private events for compliance and monitoring purposes.

Privacy Benefits

• Confidential transfers: Transfer amounts and participants are only visible to involved parties
• Private approvals: Allowance changes are only visible to owner and spender
• Regulatory compliance: Auditors can monitor activity while maintaining user privacy
• Selective disclosure: Events are only visible to authorized viewers

This approach maintains full ERC-3643 compliance while adding programmable privacy through the private events system.

Prerequisites

• Node.js (v14 or higher)
• pnpm (recommended)
• Hardhat
• Access to Silent Data credentials (for Silent Data deployment)

Project Structure

The token implementation is located in the contracts/ucef-3643.sol file. The root directory includes:

• Test fixtures
• Deployment script (scripts/deploy-suite.ts)
• Ignition module (ignition/modules/UCEF3643.ts)

Testing

Running Tests

1. Clone the repository:

   git clone <repository-url>
   cd confidential-erc-3643

2. Install dependencies:

   pnpm install

3. Compile contracts:

   pnpm compile

4. Run all tests:

   pnpm test

Deployment

Local Development

1. Start local Hardhat node:

   pnpm chain

2. Configure environment:

   Create a .env file in the root directory:

   PRIVATE_KEY=<deployer_private_key>

3. Deploy using Ignition:

   pnpm deploy:module UCEF3643

Silent Data Deployment

1. Configure environment:

   Create a .env file with Silent Data credentials:

   PRIVATE_KEY=<deployer_private_key>
   RPC_URL=<silent_data_rpc_url>
   CHAIN_ID=<silent_data_chain_id>

2. Deploy to Silent Data:

   pnpm deploy:module UCEF3643 silentdata

Available Modules

Module Name	Description
UCEF3643	Basic UCEF3643 token deployment without initialization
UCEF3643Init	UCEF3643 token deployment with mock registry/compliance and initialization
UCEF3643Proxy	UCEF3643 token deployment with proxy pattern for upgradability

Deployment Script

The deployment script (scripts/deploy-suite.ts) deploys the complete T-REX suite including:

• ClaimTopicsRegistry
• TrustedIssuersRegistry
• IdentityRegistryStorage
• IdentityRegistry
• ModularCompliance
• TREXImplementationAuthority
• Token implementation (UCEF3643)

To use the deployment script:

pnpm script deploy-suite

To use the deployment script with Silent Data network:

pnpm script deploy-suite silentdata

The script will output the deployment addresses to the a file DeploymentOutput.json in the out directory. It's possible to export the private keys of the accounts by prepending the EXPORT_PRIVATE_KEYS environment variable set to true.

EXPORT_PRIVATE_KEYS=true pnpm script deploy-suite

Troubleshooting

If you encounter issues:

1. Clean build artifacts:

   pnpm clean

2. Recompile contracts:

   pnpm compile

3. Verify environment configuration

4. Check network connectivity

5. Ensure sufficient funds for deployment

Important Notes

• Always test thoroughly on local network before deployment
• Keep private keys and API credentials secure
• Back up deployment addresses and transaction hashes
• Monitor gas prices for optimal deployment timing
• Ensure all required contracts are properly deployed in the correct order

Development Workflow

1. Make changes to contracts
2. Run tests to verify changes
3. Deploy to local network for testing
4. Deploy to testnet if required
5. Deploy to production network

Security Considerations

• Verify all contract interactions
• Implement proper access controls
• Test all security-critical functions
• Review compliance requirements
• Monitor for potential vulnerabilities

License

This project is licensed under the MIT License - see the LICENSE file for details.