rust-poseidon-bn254-pure
------------------------

Self-contained (no external dependencies), pure Rust implementation of Poseidon 
and Poseidon2 hash functions over the BN254 curve's scalar field, using 32 bit 
limbs internally.

It's intended to be used on 32-bit platforms, eg. 32-bit RISC-V (rv32im)
(though porting to 64 bits shouldn't be a big effort).

The algebra implementation is based on [`zikkurat-algebra`](https://github.com/faulhornlabs/zikkurat-algebra/)
and [`staging-agda`](https://github.com/faulhornlabs/staging-agda/).

### Status

Currently, only Poseidon2 with `t=3` is implemented.

### TODO

- [ ] optimize squaring to use less multiplications (?)
- [ ] benchmark RISC-V cycles
- [ ] add more Poseidon2 state widths (not just `t=3`)
- [ ] implement `circomlib`-compatible Poseidon
- [ ] add a test-suite; in particular, more complete testing of the field operations
- [ ] add a 64 bit version
- [ ] further optimizations