Constantine
Constantine is a high-performance cryptography library designed for use in proof systems and blockchain protocols. It aims to provide secure and efficient cryptographic implementations, emphasizing the need for constant-time operations to protect against timing attacks.
Overview
Constantine offers constant-time implementations of various cryptographic primitives. This means it performs operations in a way that doesn't reveal secret data through side-channel attacks, which can occur when attackers measure the time taken to execute cryptographic operations. This library is specifically optimized for use in blockchain technologies and zero-knowledge proof systems, where security and performance are critical.
Public API: Curves & Protocols
Constantine provides a rich public API for numerous cryptographic protocols and elliptic curves essential for secure communication and data integrity. The library aims to meet various cryptographic goals such as confidentiality, authentication, integrity, and non-repudiation. This makes it a versatile tool for developers needing secure cryptographic functionalities.
Supported Protocols
Constantine supports several protocols across different programming languages like Nim, C, Rust, and Go. Some of the key protocols include:
- Ethereum BLS Signatures: Offers full support across all mentioned languages, ensuring interoperability and security for Ethereum networks.
- Ethereum KZG Commitments: Fully supported for reliable polynomial commitments used in Ethereum’s scaling solutions.
- Zk Accel Layer for Halo2 Proof System: Available in Rust for experimental use, aiding in developing sophisticated zero-knowledge proofs.
Supported Elliptic Curves
Elliptic curve cryptography is vital in various cryptographic applications. Constantine supports:
- BN254-Snarks & BLS12-381: Widely used for zk-SNARKs and other cryptography-related applications.
- Pasta Curves (Pallas & Vesta): Ensures robust support for zk-STARKs and similar cryptographic tasks.
All operations on these elliptic curves are performed in constant-time to prevent leaks through side-channel attacks.
General Cryptography
The library also includes implementations for general cryptographic tasks. This involves support for SHA256 hashing and cryptographically secure random number generation across all supported languages.
High-Performance Threadpool
For the Nim programming language, Constantine provides a high-performance threadpool that enhances task parallelism, crucial for cryptographic operations requiring extensive computation. This includes advanced features like nested parallelism and complex reduction operations, optimizing the use of multi-core processors.
Installation
Constantine can be installed and used via several programming languages:
- Rust: Recommended to use with Clang for better performance, especially if targeting systems without native assembly optimizations.
- Go: Utilizes a separate modfile for safe package testing, prioritizing security by avoiding external dependencies.
- C: Offers flexibility in compiler choice, with detailed instructions for compiling libraries.
- Nim: Easily install the development version using nimble for experimentation and implementation.
Dependencies & Requirements
Constantine emphasizes security and performance by maintaining zero external dependencies. It requires modern compilers like GCC 7 or Clang 14 for efficient and secure code generation. Attention to assembly usage further enhances both security and performance, making Constantine a reliable cryptography library for developers.
Security
Constantine is designed to mitigate common attack vectors in cryptography, though it is provided as is, without guarantees. Users are encouraged to thoroughly evaluate it against their specific security needs. Its constant-time implementations aim to resist sophisticated attacks such as timing or side-channel attacks effectively.
Why Nim?
Nim is chosen for its flexibility and performance. It allows seamless compilation to different languages and offers powerful features like rich type systems, compile-time evaluation, inline assembly support, and planned support for formal verification. These features make it an ideal choice for implementing cryptography that matches or exceeds C-level performance.
Licensing
Constantine is open-source and distributed under either the MIT License or Apache License 2.0, giving users the flexibility to choose their preferred licensing agreement. The library's design ensures no external dependencies, maintaining the integrity and security of its cryptographic implementations.