Update README.md

Author: albertodebortoli

README.md

@@ -1,3 +1,113 @@
 # ToggleCipher
 
-A description of this package.
+A Swift command-line tool that provides secure encryption and decryption capabilities using modern cryptographic algorithms. Built with Apple's CryptoKit framework for high-performance, secure cryptographic operations.
+
+## Features
+
+- **ChaCha20-Poly1305 Encryption**: Industry-standard authenticated encryption algorithm
+- **Command-Line Interface**: Easy-to-use CLI for encryption and decryption operations
+- **Swift Package Manager**: Modern Swift package with comprehensive testing
+- **Secure Key Handling**: Uses SHA-256 hashing for key derivation
+- **Base64 Encoding**: Human-readable output format for encrypted data
+
+## Requirements
+
+- macOS 12.0 or later
+- Swift 6.0 or later
+- Xcode 14.0 or later (for development)
+
+## Installation
+
+### Download Pre-built Binary
+
+Download the latest pre-built binary from [GitHub Releases](https://github.com/TogglesPlatform/ToggleCipher/releases):
+
+```bash
+# Download and install (replace VERSION with the latest version)
+curl -L https://github.com/TogglesPlatform/ToggleCipher/releases/download/VERSION/ToggleCipher -o /usr/local/bin/ToggleCipher
+chmod +x /usr/local/bin/ToggleGen
+```
+
+### Building from Source
+
+1. Clone the repository:
+   ```bash
+   git clone https://github.com/TogglesPlatform/ToggleCipher.git
+   cd ToggleCipher
+   ```
+
+2. Build the executable:
+   ```bash
+   swift build -c release
+   ```
+
+3. The executable will be available at `.build/release/ToggleCipher`
+
+## Usage
+
+ToggleCipher provides two main commands: `encrypt` and `decrypt`.
+
+### Encrypting Data
+
+```bash
+ToggleCipher encrypt --algorithm chaChaPoly --key "your-secret-key" --value "data to encrypt"
+```
+
+**Example:**
+```bash
+ToggleCipher encrypt --algorithm chaChaPoly --key "mySecretKey123" --value "Hello, World"
+```
+
+**Output:**
+```
+Plaintext value: "Hello, World"
+Encrypted value: "9bnthawCQI+H5gRFM+4i7ng491R7ZnQ4Iqd5nCuKZ/hAYf6AzDV/5w=="
+```
+
+### Decrypting Data
+
+```bash
+ToggleCipher decrypt --algorithm chaChaPoly --key "your-secret-key" --value "encrypted-data"
+```
+
+**Example:**
+```bash
+ToggleCipher decrypt --algorithm chaChaPoly --key "mySecretKey123" --value "base64-encoded-encrypted-data"
+```
+
+**Output:**
+```
+Encrypted value: "9bnthawCQI+H5gRFM+4i7ng491R7ZnQ4Iqd5nCuKZ/hAYf6AzDV/5w=="
+Decrypted value: "Hello, World"
+```
+
+### Command-Line Options
+
+| Option | Description | Required |
+|--------|-------------|----------|
+| `--algorithm` | The encryption algorithm to use (currently supports: `chaChaPoly`) | Yes |
+| `--key` | The secret key used for encryption/decryption | Yes |
+| `--value` | The data to encrypt or decrypt | Yes |
+
+## Supported Algorithms
+
+Currently, ToggleCipher supports the following encryption algorithms:
+
+- **ChaCha20-Poly1305** (`chaChaPoly`): A high-speed, authenticated encryption algorithm that provides both confidentiality and authenticity
+
+## Security Considerations
+
+- **Key Management**: Ensure your encryption keys are stored securely and never hard-coded in your applications
+- **Key Derivation**: Keys are processed through SHA-256 hashing before use, providing consistent key lengths
+- **Authenticated Encryption**: ChaCha20-Poly1305 provides both encryption and authentication, protecting against tampering
+- **Secure Random**: The encryption process uses cryptographically secure random number generation
+
+## License
+
+This project is licensed under the terms specified in the [LICENSE](LICENSE) file.
+
+## Contributing
+
+Contributions are welcome! Please feel free to submit a Pull Request.
+
+For more information about the ChaCha20-Poly1305 algorithm, see [RFC 8439](https://tools.ietf.org/html/rfc8439).