Locket

A minimal EVM account generator for testing and development.

Locket generates Ethereum-compatible accounts (private keys, public keys, and addresses) using secure cryptographic standards. All generated keys are saved to a JSON file for easy access during development and testing.

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CRITICAL SECURITY WARNING

Locket Keys are from TESTING ONLY — DO NOT USE WITH REAL FUNDS

This tool writes unencrypted private keys directly to disk (accounts.json).

NEVER use Locket-generated accounts for:

• Real cryptocurrency transactions
• Production environments
• Storing actual funds
• Mainnet operations

Intended for LOCAL TESTING ONLY.

If the user chooses to use these keys with real funds, the user does so entirely at the user's own risk. We strongly recommend against it.

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What Does Locket Do?

Locket generates valid Ethereum accounts by:

1. Creating a cryptographically secure private key (secp256k1)
2. Deriving the corresponding public key
3. Computing the Ethereum address from the public key hash
4. Saving all key material to accounts.json in a structured format

The user can mention the number of account N, they want to generate as a variable to the cargo run command. Locket will generate the JSON-formatted N evm accounts to the accounts.json file.

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Installation

Prerequisites

• Rust (1.70 or later recommended)
  • Install from https://rustup.rs/

Clone the Repository

git clone https://github.com/romanticNomad/Locket.git
cd Locket

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Usage

Generate a New Account

Simply run (N must be a non-zero natural number):

cargo run -- accounts N

In case no variable N is provided, Locket will default to N=1.

What happens:

• Locket generates a new EVM account
• The account is saved to accounts.json in the project directory
• If accounts.json doesn't exist, it will be created
• Each new account is indexed as account1, account2, account3, etc.

Example Output

After running (say) cargo run -- accounts 2, the user will see:

Generated 2 account(s) in accounts.json

The accounts.json file will look like this:

{
  "account1": {
    "pvt_key": "0x1a2b3c4d5e6f78...",
    "pub_key": "0x04a1b2c3d4e5f6...",
    "address": "0x742d35Cc6634C0..."
  },
  "account2": {
    "pvt_key": "0x9876543210fedc...",
    "pub_key": "0x04f6e5d4c3b2a1...",
    "address": "0x5aAeb6053F3E94..."
  }
}

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Output Format

Each generated account contains:

Field	Description	Example
pvt_key	32-byte private key (hex with 0x prefix)	0x1a2b3c...
pub_key	Uncompressed secp256k1 public key (65 bytes)	0x04a1b2c3...
address	Ethereum address (20 bytes)	0x742d35Cc...

All values are hex-encoded and compatible with standard Ethereum tooling (web3.js, ethers.js, Hardhat, Foundry, etc.).

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Use Cases

Locket is ideal for:

Local development — Generate test accounts for smart contract development
CI/CD pipelines — Create deterministic test fixtures
Testing frameworks — Provide accounts for automated tests (Hardhat, Foundry, etc.)
Cross-language verification — Export keys for use in JavaScript, Python, Go, etc.
Prototyping — Quickly generate accounts for signing service development

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Security Best Practices

DO:

• Use Locket only in isolated development environments
• Delete accounts.json when no longer needed
• Keep the repository and accounts.json out of version control (already in .gitignore)
• Use testnet funds only (Sepolia, Goerli, etc.)

DON'T:

• Commit accounts.json to Git
• Use generated keys on mainnet
• Share accounts.json publicly
• Store real funds in Locket-generated accounts

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File Structure

locket/
├── src/
│   ├── main.rs          # Core key generation logic
│   └── serialize.rs     # JSON export structures
├── Cargo.toml           # Rust dependencies
├── LICENSE              # MIT License
├── .gitignore           # Excludes accounts.json from Git
└── accounts.json        # Generated accounts (created on first run)

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How It Works (Technical Overview)

Locket uses industry-standard cryptographic primitives:

• Private Key: Generated using OS-backed randomness (OsRng) via the k256 crate
• Public Key: Derived using secp256k1 elliptic curve (uncompressed format: 0x04 || X || Y)
• Address: Computed as the last 20 bytes of keccak256(public_key[1..])

All operations are deterministic and follow Ethereum's key derivation standards.

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License

MIT License — see LICENSE for details.

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Contributing

Contributions are welcome! Feel free to open issues or submit pull requests.

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Need Help?

• Issues: GitHub Issues
• Questions: Open a discussion in the repository

Happy Testing