Warning

This crate has been archived. Development has moved to the zksync-crypto repository. Please use it instead.

"FF community edition"

This library is community maintained fork of the original ff library by Sean Bowe. Name of the library is changed to allow publishing to the crates.io

Original ff

ff is a finite field library written in pure Rust, with no unsafe{} code.

Disclaimers

• This library does not provide constant-time guarantees.

Usage

Add the ff_ce crate to your Cargo.toml:

[dependencies]
ff_ce = "0.6"

The ff_ce crate contains Field, PrimeField, PrimeFieldRepr and SqrtField traits. See the documentation for more.

#![derive(PrimeField)]

If you need an implementation of a prime field, this library also provides a procedural macro that will expand into an efficient implementation of a prime field when supplied with the modulus. PrimeFieldGenerator must be an element of Fp of p-1 order, that is also quadratic nonresidue.

First, enable the derive crate feature:

[dependencies]
ff = { ..., features = ["derive"] }

And then use the macro like so:

extern crate rand;
#[macro_use]
extern crate ff_ce;

#[derive(PrimeField)]
#[PrimeFieldModulus = "52435875175126190479447740508185965837690552500527637822603658699938581184513"]
#[PrimeFieldGenerator = "7"]
struct Fp(FpRepr);

And that's it! Fp now implements Field and PrimeField. Fp will also implement SqrtField if supported. The library implements FpRepr itself and derives PrimeFieldRepr for it.

License

Licensed under either of

• Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.