================================================================================ ZENTH CRYPTO SERVICE - DOCUMENTATION ================================================================================ Author Doctor ================================================================================ Zenth Crypto Service Library A Comprehensive Cryptographic Framework ================================================================================ Status of This Memo This document specifies a comprehensive cryptographic library implementation for the Rust programming language. This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited. Copyright Notice Copyright (c) 2024 Doctor. All rights reserved. Abstract This document describes the Zenth Crypto Service, a comprehensive cryptographic library written in Rust that provides a unified interface for symmetric and asymmetric encryption, cryptographic hashing, key exchange protocols, and post-quantum cryptography. The library implements industry-standard algorithms and provides secure, high-performance cryptographic operations suitable for production environments. Table of Contents 1. Introduction .................................................. 2. Architecture Overview ......................................... 3. Cryptographic Modules ......................................... 4. Security Considerations ....................................... 5. Performance Characteristics ................................... 6. Implementation Details ........................................ 7. Testing and Validation ........................................ 8. Future Considerations ......................................... 9. References .................................................... 1. Introduction The Zenth Crypto Service is a comprehensive cryptographic library designed to provide secure, high-performance cryptographic operations for modern applications. Built in Rust, it leverages the language's memory safety guarantees and performance characteristics to deliver a robust cryptographic framework. The library addresses the growing need for comprehensive cryptographic solutions that can handle both traditional and post-quantum cryptographic algorithms, providing a unified interface for developers to implement secure communication and data protection. 1.1. Design Goals The primary design goals of the Zenth Crypto Service include: - Comprehensive Coverage: Support for symmetric and asymmetric encryption, hashing, key exchange, and post-quantum cryptography - Security First: Implementation of industry best practices and secure coding patterns - Performance: High-performance implementations suitable for production environments - Modularity: Clean, modular architecture for easy maintenance and extension - Standards Compliance: Adherence to established cryptographic standards and recommendations 1.2. Target Applications The library is designed for use in: - Secure messaging applications - Data encryption and storage systems - Blockchain and cryptocurrency applications - IoT device security - Enterprise security solutions - Research and educational purposes 2. Architecture Overview The Zenth Crypto Service follows a modular architecture pattern, organizing cryptographic functionality into distinct, well-defined modules: +------------------+------------------+------------------+ | Symmetric | Asymmetric | Hashing | | Encryption | Encryption | Functions | +------------------+------------------+------------------+ | Key Exchange | Key Encaps. | Encoding | | Protocols | Mechanisms | Formats | +------------------+------------------+------------------+ | Key Derivation | Utilities | Error | | Functions | & Helpers | Handling | +------------------+------------------+------------------+ 2.1. Module Structure The library is organized into the following primary modules: - asymetric/: Asymmetric cryptographic operations (RSA) - symetric/: Symmetric cryptographic operations (AES, Serpent, etc.) - hashing/: Cryptographic hash functions and MACs - encoding/: Data encoding and serialization (Base64, Hex, PEM) - exchange/: Key exchange protocols (Diffie-Hellman, Curve25519) - kem/: Key Encapsulation Mechanisms (Kyber, ML-KEM) - kdf/: Key Derivation Functions (Argon2id) - utils/: Utility functions and constant-time operations - errors/: Centralized error handling and types 2.2. Dependencies and External Libraries The implementation leverages several well-established cryptographic libraries: - BoringSSL: High-performance cryptographic primitives - libcrux: Post-quantum cryptographic implementations - curve25519-dalek: Elliptic curve cryptography - rsa: RSA implementation with OAEP padding - argon2: Password hashing and key derivation 3. Cryptographic Modules 3.1. Symmetric Encryption The symmetric encryption module provides implementations of major block ciphers and stream ciphers: 3.1.1. Advanced Encryption Standard (AES) - AES-256-CBC: Cipher Block Chaining mode - AES-256-CTR: Counter mode for stream-like operation - AES-256-GCM: Galois/Counter Mode with authentication 3.1.2. Serpent Cipher - Serpent-256-CBC: High-security block cipher - Serpent-256-CTR: Counter mode implementation 3.1.3. Twofish Cipher - Twofish-256-CBC: AES finalist cipher - Twofish-256-CTR: Counter mode implementation 3.1.4. ChaCha20-Poly1305 - Authenticated encryption with associated data (AEAD) - High-performance stream cipher with built-in authentication 3.2. Asymmetric Encryption 3.2.1. RSA Implementation - RSA-4096: 4096-bit key size for high security - OAEP Padding: Optimal Asymmetric Encryption Padding - SHA-512: Hash function for OAEP padding 3.3. Cryptographic Hash Functions The hashing module provides comprehensive hash function support: 3.3.1. SHA Family - SHA-1: Legacy hash function (for compatibility) - SHA-256: 256-bit Secure Hash Algorithm - SHA-512: 512-bit Secure Hash Algorithm 3.3.2. SHA-3 Family - SHA3-256: Keccak-based 256-bit hash - SHA3-512: Keccak-based 512-bit hash 3.3.3. Message Authentication Codes (MACs) - HMAC-SHA1: Hash-based Message Authentication Code - HMAC-SHA256: HMAC with SHA-256 - HMAC-SHA3-256: HMAC with SHA3-256 - HMAC-SHA3-512: HMAC with SHA3-512 3.3.4. Integrity Checking - CRC32: Cyclic Redundancy Check for data integrity 3.4. Key Exchange Protocols 3.4.1. Diffie-Hellman - Traditional key exchange protocol - Secure key agreement between parties 3.4.2. Curve25519 - Elliptic curve Diffie-Hellman - High-performance key exchange - Signal Protocol compatibility 3.5. Post-Quantum Cryptography 3.5.1. Key Encapsulation Mechanisms (KEMs) - Kyber-768: NIST-selected post-quantum KEM - Kyber-1024: Higher security variant - ML-KEM-1024: Module-Lattice-based KEM 3.6. Key Derivation Functions 3.6.1. Argon2id - Memory-hard password hashing - Resistance to side-channel attacks - Configurable parameters for security/performance trade-offs 3.7. Encoding and Serialization 3.7.1. Base64 Encoding - Secure base64 encoding/decoding - URL-safe variants 3.7.2. Hexadecimal Encoding - Binary to hexadecimal conversion - Secure hex encoding 3.7.3. PEM Format - Privacy-Enhanced Mail format - Public/private key serialization 4. Security Considerations 4.1. Memory Safety The implementation leverages Rust's memory safety guarantees to prevent common vulnerabilities such as buffer overflows and use-after- free errors. Critical security data is automatically zeroized when no longer needed. 4.2. Constant-Time Operations The library implements constant-time comparison functions to prevent timing attacks. All cryptographic operations that involve secret data are designed to execute in constant time regardless of input values. 4.3. Random Number Generation All cryptographic operations requiring randomness use the operating system's cryptographically secure random number generator (OSRNG). This ensures high-quality entropy for key generation and nonce creation. 4.4. Key Management The library provides secure key generation and management facilities. Private keys are handled with appropriate security measures, and key material is protected against memory dumps and side-channel attacks. 4.5. Algorithm Selection The library implements only well-vetted, industry-standard cryptographic algorithms. Deprecated or weak algorithms are either not included or clearly marked for legacy compatibility only. 5. Performance Characteristics 5.1. Benchmarking The library includes comprehensive benchmarking using the Criterion framework. Performance tests cover: - Encryption/decryption throughput - Hash function performance - Key generation speed - Memory usage patterns 5.2. Optimization Strategies - Native code compilation for maximum performance - SIMD instruction utilization where available - Parallel processing support via Rayon - Zero-copy operations where possible 5.3. Memory Efficiency - Minimal memory allocations during cryptographic operations - Efficient buffer management - Automatic cleanup of sensitive data 6. Implementation Details 6.1. Error Handling The library uses Rust's Result type for comprehensive error handling. All cryptographic operations return Result to ensure proper error propagation and handling. 6.2. API Design The API is designed for ease of use while maintaining security: ```rust // Example: AES-GCM encryption let key = [1u8; 32]; let nonce = [2u8; 12]; let plaintext = b"Hello, World!"; let mut enc = Aes256GcmEncryption::new(&key, &nonce, &[])?; let mut buffer = plaintext.to_vec(); enc.encrypt(&mut buffer); let tag = enc.compute_tag(); ``` 6.3. Thread Safety All cryptographic operations are thread-safe and can be used concurrently across multiple threads without additional synchronization. 6.4. Configuration The library provides sensible defaults for all cryptographic parameters while allowing customization for specific use cases. 7. Testing and Validation 7.1. Test Coverage The library includes comprehensive test suites covering: - Unit tests for individual functions - Integration tests for complete workflows - Property-based testing for cryptographic properties - Known Answer Tests (KATs) for algorithm validation 7.2. Test Data Test vectors are provided in JSON format for easy validation against reference implementations and standards. 7.3. Continuous Integration The project includes automated testing and validation pipelines to ensure code quality and security. 8. Future Considerations 8.1. Post-Quantum Migration The library is designed to facilitate the transition to post- quantum cryptography. New algorithms can be easily integrated as they become standardized. 8.2. Algorithm Updates The modular architecture allows for easy updates and additions of new cryptographic algorithms as they become available and standardized. 8.3. Performance Improvements Ongoing optimization efforts focus on: - Hardware acceleration support - SIMD instruction utilization - Parallel processing enhancements - Memory usage optimization 8.4. Standards Compliance The library will continue to evolve to maintain compliance with emerging cryptographic standards and best practices. 9. References 9.1. Normative References [NIST.FIPS.197] National Institute of Standards and Technology, "Advanced Encryption Standard (AES)", FIPS PUB 197, November 2001. https://nvlpubs.nist.gov/nistpubs/fips/nist.fips.197.pdf [NIST.SP.800-38A] National Institute of Standards and Technology, "Recommendation for Block Cipher Modes of Operation: Methods and Techniques", SP 800-38A, December 2001. https://nvlpubs.nist.gov/nistpubs/legacy/sp/nistspecialpublication800-38a.pdf [NIST.SP.800-38D] National Institute of Standards and Technology, "Recommendation for Block Cipher Modes of Operation: Galois/Counter Mode (GCM) and GMAC", SP 800-38D, November 2007. [RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed-Hashing for Message Authentication", RFC 2104, February 1997. https://datatracker.ietf.org/doc/html/rfc2104 [RFC3447] Jonsson, J. and B. Kaliski, "Public-Key Cryptography Standards (PKCS) #1: RSA Cryptography Specifications Version 2.1", RFC 3447, February 2003. https://datatracker.ietf.org/doc/html/rfc3447 9.2. Informative References [RFC7748] Langley, A., Hamburg, M., and S. Turner, "Elliptic Curves for Security", RFC 7748, January 2016. https://www.rfc-editor.org/rfc/rfc7748.html [NIST.SP.800-208] National Institute of Standards and Technology, "Recommendation for Stateful Hash-Based Signature Schemes", SP 800-208, October 2020. https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-208.pdf ================================================================================