A collection of Elliptic Curves for ZkCrypto traits
This library provides efficient and flexible implementations of various halo2-friendly elliptic curves, originally implementing the BN256 curve with traits from the zkcrypto
ecosystem,
The implementations were originally ported from matterlabs/pairing and zkcrypto/bls12-381, but have been extended and optimized to cover a broader set of curves and use cases. Since its initial release, the library has expanded to include additional curves, along with the following features:
secp256k1
,secp256r1
,pluto
,eris
andgrumpkin
curves, enhancing its usability across a range of cryptographic protocols.- Assembly optimizations leading to significantly improved performance.
- Various features related to serialization and deserialization of curve points and field elements.
- Curve-specific optimizations and benchmarking capabilities.
Controlling parallelism
halo2curves
currently uses rayon for parallel
computation.
The RAYON_NUM_THREADS
environment variable can be used to set the number of
threads.
When compiling to WASM-targets, notice that since version 1.7
, rayon
will fallback automatically (with no need to handle features) to require getrandom
in order to be able to work.
For more info related to WASM-compilation.
See: Rayon: Usage with WebAssembly for more info.
Benchmarks
Benchmarking is supported through the use of Rust's built-in test framework. Benchmarks can be run without assembly optimizations:
$ cargo test --profile bench test_field -- --nocapture
or with assembly optimizations:
$ cargo test --profile bench test_field --features asm -- --nocapture
Additional Features
-
Derivation of Serialize/Deserialize: The library supports Serde's
Serialize
andDeserialize
traits for field and group elements, making it easier to integrate curve operations into serialization-dependent workflows. -
Hash to Curve: For the
bn256::G1
andgrumpkin::G1
curves,hash_to_curve
is implemented, enabling more efficient hash-and-sign signature schemes. -
Lookup Table: A pre-computed lookup table is available for
bn256::Fr
, accelerating conversion fromu16
to montgomery representation.
Structure
The library's top-level directories are organized as follows:
benches
: Contains benchmarking tests.script
: Contains utility scripts.src
: Contains the source code of the library, further subdivided into modules for each supported curve (bn256
,grumpkin
,secp256k1
,secp256r1
,secq256k1
,pasta
,pluto
,eris
) and additional functionalities (derive
,tests
).