Crate sumhash

This repository contains a Rust implementation of subset-sum hash function designed by the Algorand project.

The reference implementation is written in Go and can be found in the go-sumhash repository. You can also refer to the spec to see a formal description of the hash function.

This implementation isn’t a literal port of the Go repository since the official implementation wouldn’t lead to idiomatic Rust. In this library, we implement a Sumhash512Core core that can be wrapped with CoreWrapper. If you’re interested in an earlier version which was a direct port of the reference implementation, see the legacyport branch.

To have confidence that the implementation is correct, all tests from go-sumhash where included in the repo. The tests rely on randomness generated with Shake256 using particular seeds that were honored such that we can expect each inputo to have an exact output result with the official implementation.

This library has a AlgorandSumhash512Core type alias which facilitates a default configuration for Sumhash512Core that utilizes the official seed for the Algorand blockchain state proofs.

This library isn’t audited or ready for production use, nor is it an official implementation.

Examples

Using the Algorand instance configuration:

use sumhash::sumhash512core::AlgorandSumhash512Core;
use digest::{core_api::CoreWrapper, FixedOutput, Update};

let mut h = CoreWrapper::<AlgorandSumhash512Core>::default();
h.update("hello world".as_bytes());
let output = h.finalize_fixed();
println!("Result: {}", hex::encode(&output));

Generic flavor providing your own seed.

use sumhash::sumhash512core::Sumhash512Core;
use digest::{core_api::CoreWrapper, FixedOutput, Update};

let mut salt = [0; 64];
salt[0] = 0x13;
salt[1] = 0x37;
let mut h = CoreWrapper::from_core(Sumhash512Core::new_with_salt(salt));
h.update("hello world".as_bytes());
let output = h.finalize_fixed();
println!("Result: {}", hex::encode(&output));

Modules

compress

compress represents the compression function which is performed on a message.

sumhash512core

sumhash512core is a sumhash core implementation for 512 bit output.