dusk-hades 0.24.1

Implementation of Hades252 permutation algorithm over the Bls12-381 Scalar field.
Documentation 
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# Hades252 (deprecated)

| :exclamation: This crate is deprecated. |
|---------------------------------------------|
The hades permutation moved into [`dusk-poseidon`](https://github.com/dusk-network/Poseidon252).

Implementation of Hades252 permutation algorithm over the Bls12-381 Scalar field.

## Documentation

To generate the `Hades252` documentation:

```sh
make doc
make doc-internal
```

## Use

Run the following to add `Hades252` to the dependency section of your project's 'Cargo.toml':

```toml
cargo add dusk-hades
```

`Hades252` has a `width` equals to `5`; it's possible to use a different value,
see [How to generate the assets](assets/HOWTO.md).

## Parameters

- p = `0x73eda753299d7d483339d80809a1d80553bda402fffe5bfeffffffff00000001`

- Security level is 117 -120 bits of security [NCCG] bits.

- width = 5

- Number of full rounds = 8 . There are four full rounds at the beginning and four full rounds at the end,
  where each full round has `WIDTH` quintic S-Boxes.

- Number of partial rounds = 59, where each partial round has one quintic S-Box and (width-1) identity functions.

- Number of round constants = 960

## Example for `ScalarStrategy`

```rust
use dusk_bls12_381::BlsScalar;
use dusk_hades::{ScalarStrategy, Strategy, WIDTH};

// Generate the inputs that will permute.
// The number of values we can input is equivalent to `WIDTH`

let input = vec![BlsScalar::from(1u64); dusk_hades::WIDTH];
let mut output = input.clone();

let mut strategy = ScalarStrategy::new();
strategy.perm(output.as_mut_slice());

assert_ne!(&input, &output);
assert_eq!(input.len(), output.len());
```

## Deviations

- Round constants for the full rounds are generated following: [https://extgit.iaik.tugraz.at/krypto/hadesmimc/blob/master/code/calc_round_numbers.py](https://extgit.iaik.tugraz.at/krypto/hadesmimc/blob/master/code/calc_round_numbers.py)

- The MDS matrix is a cauchy matrix, the method used to generate it, is noted in section "Concrete Instantiations Poseidon and Starkad"

## Reference

[https://eprint.iacr.org/2019/458.pdf](https://eprint.iacr.org/2019/458.pdf)