8# G-Naira (gNGN) - Central Bank Digital Currency

Overview

G-Naira (gNGN) is a blockchain-based Central Bank Digital Currency (CBDC) solution designed to enhance transparency and accountability in a country's financial sector. This implementation leverages blockchain technology to provide a secure, traceable, and efficient digital currency system.

Table of Contents

• Features
• Architecture
• Security Measures
• Technical Specifications
• Installation
• Deployment
• Contract Interaction
• Testing
• License

Features

Core Features

• ERC20 Compliant: Full compliance with ERC20 token standard for maximum interoperability
• Minting Capability: Central Bank can issue new digital currency
• Burning Capability: Removal of currency from circulation as needed
• Blacklisting: Ability to prevent specific addresses from sending or receiving tokens
• Governance: Restricted access to critical functions via the GOVERNOR role
• Multi-signature Security: Requires multiple approvals for sensitive operations

Advanced Security Features

• Rate Limiting: Caps on minting and burning per time period
• Maximum Supply Cap: Hard limit on total token supply
• Emergency Pause: Ability to halt all transfers in case of security incidents
• Comprehensive Event Logging: Full transparency of all operations

Architecture

The G-Naira system consists of a contract with integrated functionality:

GNGN Token Contract

The primary contract implementing the ERC20 token with additional CBDC-specific functionality.

• Inherits from OpenZeppelin's ERC20 and Pausable contracts
• Integrates with GovernorRole for access control
• Implements blacklisting, rate limiting, and maximum supply
• Mints initial supply (10% of max supply) to deployer during contract creatio Handles governance, access control, and multi-signature functionality for the GNGN token.
• Built on OpenZeppelin's AccessControl
• Manages GOVERNOR_ROLE assignment and verification
• Contains embedded multi-signature functionality:
  • Configurable signers and confirmation threshold
  • Transaction submission and confirmation workflow
  • Secure mint/burn operations requiring multiple approvals

This consolidated architecture makes the codebase more concise while maintaining all security features.

Security Measures

Access Control

• Operations like minting, burning, and blacklisting restricted to GOVERNOR role
• Two-factor authentication via MultiSigWallet for critical operations

Rate Limiting

• Maximum mint rate: 1,000,000 tokens per 24-hour period
• Maximum burn rate: 1,000,000 tokens per 24-hour period
• Automatic rate limit reset after time period expires

Supply Control

• Maximum supply capped at 1,000,000,000 tokens
• Prevents inflation beyond predetermined limits

Emergency Controls

• Pause functionality to stop all transfers in emergency situations
• Only executable by GOVERNOR role

Technical Specifications

Token Details

• Name: G-Naira
• Symbol: gNGN
• Decimals: 18
• Maximum Supply: 1,000,000,000 tokens
• Initial Supply: 100,000,000 tokens (10% of maximum supply)

Deployment Information

• Network: Base Sepolia Testnet
• GNGN Token Address: 0x844950A11457E6896fCf26752d4e54C52775b5e4
• Contract Verification: View on BaseScan

Installation

Prerequisites

• Node.js (>= 14.0.0)
• npm (>= 7.0.0)
• Hardhat (>= 2.12.0)

Setup

1. Clone the repository

git clone https://github.com/your-username/G-Naira.git
cd G-Naira

2. Install dependencies

npm install

Environment Configuration

The project uses environment variables for secure configuration. Create a .env file in the project root with the following variables:

# Private key for deployment (without 0x prefix)
PRIVATE_KEY=your_wallet_private_key_here

# Network RPC URLs
BASE_SEPOLIA_RPC_URL=https://base-sepolia.g.alchemy.com/v2/your-api-key

# BaseScan API Key for contract verification
BASESCAN_API_KEY=your_basescan_api_key

# Initial Governor Address
GOVERNOR_ADDRESS=your_governor_address

# Multi-signature configuration
# Comma-separated list of signer addresses (no spaces)
MULTISIG_SIGNERS=address1,address2,address3

# Number of required confirmations for transactions
MULTISIG_REQUIRED_CONFIRMATIONS=2

# Network name override (optional)
NETWORK_NAME=base-sepolia

Environment Variables Explained

Variable	Description
PRIVATE_KEY	Your wallet's private key for deploying contracts
BASE_SEPOLIA_RPC_URL	RPC endpoint for Base Sepolia testnet
BASESCAN_API_KEY	API key for verifying contracts on BaseScan
GOVERNOR_ADDRESS	Address that will have governor privileges
MULTISIG_SIGNERS	Comma-separated list of addresses that can sign multi-sig transactions
MULTISIG_REQUIRED_CONFIRMATIONS	Number of confirmations required for multi-sig operations
NETWORK_NAME	Optional override for the network name in deployment logs

Deployment

Compile Contracts

npx hardhat compile

Deploy to Local Test Network

npx hardhat node
npx hardhat run scripts/deploy.js --network localhost

Deploy to Base Sepolia

npx hardhat run scripts/deploy.js --network base-sepolia

The deployment script will:

1. Deploy the GNGN token contract
2. Set up multi-signature functionality with the signers specified in your .env file
3. Configure rate limiting and other security features
4. Wait for block confirmations on non-local networks
5. Provide verification commands

Verify Contracts

npx hardhat verify --network base-sepolia <GNGN_CONTRACT_ADDRESS>

Recent Deployment

The G-Naira token has been successfully deployed to Base Sepolia at address 0x844950A11457E6896fCf26752d4e54C52775b5e4. You can view and interact with the contract on BaseScan.

Contract Interaction

Governor Operations

Mint Tokens

// Direct mint as governor
const gngn = await ethers.getContractAt("GNGN", "GNGN_CONTRACT_ADDRESS");
await gngn.connect(governorSigner).mint(recipientAddress, ethers.utils.parseEther("1000"));

// Mint through MultiSig (requires multiple confirmations)
const multiSig = await ethers.getContractAt("MultiSigWallet", "MULTISIG_CONTRACT_ADDRESS");
await multiSig.connect(signer1).submitMintTransaction(recipientAddress, ethers.utils.parseEther("1000"));
await multiSig.connect(signer2).confirmTransaction(txIndex);

Burn Tokens

// Direct burn as governor
await gngn.connect(governorSigner).burn(holderAddress, ethers.utils.parseEther("500"));

// Burn through MultiSig
await multiSig.connect(signer1).submitBurnTransaction(holderAddress, ethers.utils.parseEther("500"));
await multiSig.connect(signer2).confirmTransaction(txIndex);

Blacklist Operations

// Blacklist an address
await gngn.connect(governorSigner).blacklist(suspiciousAddress);

// Remove from blacklist
await gngn.connect(governorSigner).unblacklist(rehabilitatedAddress);

// Check blacklist status
const isBlacklisted = await gngn.isBlacklisted(checkAddress);

Emergency Functions

// Pause all transfers
await gngn.connect(governorSigner).pause();

// Resume operations
await gngn.connect(governorSigner).unpause();

Token Operations

Transfer Tokens

// Standard ERC20 transfer
await gngn.connect(userSigner).transfer(recipientAddress, ethers.utils.parseEther("100"));

// Transfer with approval
await gngn.connect(userSigner).approve(spenderAddress, ethers.utils.parseEther("100"));
await gngn.connect(spenderSigner).transferFrom(userAddress, recipientAddress, ethers.utils.parseEther("100"));

Testing

Run All Tests

npx hardhat test

Automated Tests

npm test

This will run the test suite that verifies all contract functionality including:

• Basic ERC20 operations
• Governance functionality
• Multi-signature operations
• Rate limiting and blacklisting features

Test Coverage

npx hardhat coverage

Manual Testing with Scripts

A test script is provided to interact with the deployed contract:

npx hardhat run scripts/test-gngn.js --network base-sepolia

This script will:

• Connect to the deployed contract
• Display contract information
• Check balances and roles
• Test mint and transfer operations if you have the appropriate permissions

Interacting via Block Explorer

You can interact with the deployed G-Naira contract directly through the Base Sepolia block explorer:

1. Access the contract on BaseScan:

   • Visit https://sepolia.basescan.org/address/0x844950A11457E6896fCf26752d4e54C52775b5e4

2. Connect your wallet:

   • Click on the "Contract" tab
   • Select "Write Contract"
   • Click "Connect to Web3" to connect your MetaMask or other wallet
   • Ensure your wallet is connected to Base Sepolia network

3. Read Contract Data:

   • Under the "Read Contract" tab, you can:
     • Check balanceOf any address
     • View totalSupply
     • Check if an address hasRole (like GOVERNOR_ROLE)
     • View name, symbol, and decimals

4. Execute Transactions:

   • Under the "Write Contract" tab, you can:
     • transfer tokens to another address
     • If you have GOVERNOR_ROLE, you can:
       • mint new tokens
       • burn tokens
       • addGovernor to add new governors
       • setupMultiSig to configure multi-signature functionality
       • blacklistAddress to restrict addresses

5. View Token Holders:

   • The "Token Holders" section shows addresses holding gNGN tokens and their balances

License

This project is licensed under the MIT License.

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