Introduction

🔐 Privacy Engine

Multi-Protocol Cryptographic Library

Multi-Protocol Encryption Library

Cryptographic library supporting Starknet, X25519, and other protocols for secure multi-recipient messaging

---

🎯 What is Privacy Engine?

The Privacy Engine is a cryptographic library that enables secure multi-recipient messaging across multiple protocols including Starknet and X25519. It features signature-based encryption, double-wrapping security, and multi-recipient support with standard cryptographic primitives.

✨ Key Features

👥 Multi-Recipient Encryption

Encrypt messages for multiple recipients simultaneously across different protocols with individual key wrapping.

🔐 Signature-Based Encryption

Double-wrapping encryption using ECDSA signatures for security and wallet integration.

🛡️ Double-Wrapping Security

Two-layer encryption: ECDH + AES-GCM inner layer, signature-derived key outer layer.

⚡ WebAssembly Performance

Rust implementation compiled to WebAssembly for browser compatibility.

🔑 Multi-Protocol Support

Built for multiple protocols including Starknet and X25519 with cryptographic operations and key recovery.

🧪 Testing

Test suite with unit tests, performance benchmarks, and integration tests.

🚀 Quick Start

use privacy_engine::encrypt::encrypt_message;
use privacy_engine::types::{RecipientInfo, Protocol};

// Encrypt a message for multiple recipients across different protocols
let message = b"Hello, secure multi-recipient world!";
let recipients = vec![
    RecipientInfo {
        pubkey: starknet_user_pubkey,  // Vec<u8>
        protocol: Protocol::Starknet,
    },
    RecipientInfo {
        pubkey: x25519_user_pubkey,    // Vec<u8>
        protocol: Protocol::X25519,
    },
];

let result = encrypt_message(message, recipients)?;

// Decrypt using the appropriate protocol and private key
// For Starknet: use signature-based decryption
// For X25519: use standard ECDH decryption

📊 Protocol Comparison

Protocol	Curve	Key Size	Signature	Key Recovery	Use Case
**Starknet**	Stark Curve	32 bytes	✅ ECDSA	✅ Yes	Blockchain, ZK systems
**X25519**	Curve25519	32 bytes	❌ No	❌ No	Standard key exchange

🔐 Signature-Based Encryption

Why Signature-Based Encryption?

The Privacy Engine implements signature-based encryption for several reasons:

1. 🔒 Enhanced Security: Double-wrapping provides an additional layer of security beyond standard ECDH

2. 👛 Wallet Integration: Seamlessly integrates with existing wallets without exposing private keys

3. 🛡️ Forward Secrecy: Ephemeral keys ensure past communications remain secure even if long-term keys are compromised

4. 🔐 Authentication: Signature verification ensures only the intended recipient can decrypt

5. ⚡ Performance: Optimized cryptographic operations

🏗️ Encryption Architecture

┌─────────────────────────────────────────────────────────────┐
│                    Privacy Engine                           │
│                 Starknet Protocol                           │
├─────────────────────────────────────────────────────────────┤
│  ┌─────────────────┐    ┌─────────────────┐                │
│  │   encrypt.rs    │    │   decrypt.rs    │                │
│  │                 │    │                 │                │
│  │ • Multi-recipient│    │ • Signature-based│               │
│  │   encryption    │    │   decryption    │                │
│  │ • Double-wrapping│    │ • Key recovery  │                │
│  └─────────────────┘    └─────────────────┘                │
├─────────────────────────────────────────────────────────────┤
│                    Starknet Layer                          │
│  ┌─────────────────┐    ┌─────────────────┐                │
│  │   starknet.rs   │    │   Key Recovery  │                │
│  │                 │    │                 │                │
│  │ • ECDSA Signing │    │ • Public Key    │                │
│  │ • ECDH Exchange │    │   Recovery      │                │
│  │ • Curve Point   │    │ • Signature     │                │
│  │   Operations    │    │   Verification  │                │
│  └─────────────────┘    └─────────────────┘                │
├─────────────────────────────────────────────────────────────┤
│                    Cryptographic Primitives               │
│  ┌─────────────────┐    ┌─────────────────┐                │
│  │   AES-256-GCM   │    │   SHA-256       │                │
│  │                 │    │                 │                │
│  │ • Message       │    │ • Key Derivation│                │
│  │   Encryption    │    │ • Hashing       │                │
│  │ • Authentication│    │ • Integrity     │                │
│  └─────────────────┘    └─────────────────┘                │
└─────────────────────────────────────────────────────────────┘

🏗️ System Architecture

┌─────────────────────────────────────────────────────────────┐
│                    Privacy Engine                           │
├─────────────────────────────────────────────────────────────┤
│  ┌─────────────────┐    ┌─────────────────┐                │
│  │   encrypt.rs    │    │   decrypt.rs    │                │
│  │                 │    │                 │                │
│  │ • Message       │    │ • Key unwrapping│                │
│  │   encryption    │    │ • Message       │                │
│  │ • Key wrapping  │    │   decryption    │                │
│  └─────────────────┘    └─────────────────┘                │
├─────────────────────────────────────────────────────────────┤
│                    Protocol Layer                           │
│  ┌─────────────────┐    ┌─────────────────┐                │
│  │   Starknet      │    │     X25519      │                │
│  │   Protocol      │    │    Protocol     │                │
│  │                 │    │                 │                │
│  │ • ECDSA         │    │ • Diffie-Hellman│                │
│  │ • Key recovery  │    │ • Key agreement │                │
│  │ • Curve25519    │    │ • X25519 curve  │                │
│  └─────────────────┘    └─────────────────┘                │
├─────────────────────────────────────────────────────────────┤
│                    Core Types                               │
│  ┌─────────────────┐    ┌─────────────────┐                │
│  │   types.rs      │    │ traits/crypto.rs│                │
│  │                 │    │                 │                │
│  │ • EncryptResult │    │ • CryptoProtocol│                │
│  │ • RecipientInfo │    │   trait         │                │
│  │ • Protocol enum │    │ • Unified API   │                │
│  └─────────────────┘    └─────────────────┘                │
└─────────────────────────────────────────────────────────────┘

📚 Documentation Sections

🚀

Getting Started

Learn how to set up and use the Privacy Engine in your project with step-by-step guides.

Get Started →

🏗️

Architecture

Understand the design principles and cryptographic foundations of the system.

Learn More →

🔧

Protocols

Detailed documentation for supported cryptographic protocols and their implementations.

Explore Protocols →

💡

Examples

Practical examples and use cases demonstrating real-world applications.

View Examples →

📖

API Reference

Complete API documentation with detailed function references and examples.

Browse API →

🔒

Security

Security considerations and best practices for production deployments.

Security Guide →

⚡ Performance Benchmarks

Protocol Performance Comparison

Key Generation

Starknet: ~2ms X25519: ~1ms

Key Agreement

Starknet: ~3ms X25519: ~2ms

Message Encryption

Both: ~1ms

Multi-Recipient

~5ms per recipient

WebAssembly Size

~500KB gzipped

Memory Usage

~10MB typical

🎯 Use Cases

💬 Secure Messaging

Multi-recipient encrypted messaging with cross-protocol support.

⛓️ Blockchain Integration

Secure communication in blockchain applications and smart contracts.

🔗 IoT Security

Device-to-device encrypted communication for IoT networks.

🎭 Zero-Knowledge Systems

Privacy-preserving cryptographic applications and ZK proofs.

🌐 Cross-Platform

Interoperability between different cryptographic schemes and platforms.

🔐 Enterprise Security

Enterprise-grade encryption for sensitive data and communications.

🚀 Getting Started

Ready to Get Started?

Install Privacy Engine and start building secure, multi-protocol applications today.

📖 Read Documentation

🐙 View on GitHub

---

Privacy Engine - Secure, multi-protocol cryptographic communication for the modern web. 🔐✨

Rust Cryptography Blockchain Zero-Knowledge Security