Crate dusk_poseidon_merkle

Poseidon Merkle Tree

Reference implementation for the Poseidon Merkle function.

The Poseidon structure will accept a number of inputs equal to the arity of the tree.

Build

A few environment variables will be read in the build process.

• POSEIDON_MERKLE_ARITY

  Represents the arity of the merkle tree. This is also the maximum number of elements the poseidon hash will accept. Defaults to 4.

• POSEIDON_MERKLE_WIDTH

  Represents the merkle tree width. Defaults to 64.

• POSEIDON_FULL_ROUNDS

  Represents the number of full rounds performed during the permutation. Defaults to 8.

• POSEIDON_PARTIAL_ROUNDS

  Represents the number of partial rounds performed during the permutation. Defaults to 59.

Example

use dusk_poseidon_merkle::{MERKLE_ARITY, Poseidon, Scalar};

let mut h = Poseidon::default();
for i in 0..MERKLE_ARITY {
    h.push(Scalar::from(i as u64)).unwrap();
}

let hash = h.hash();
println!("{:x?}", hash.as_bytes());

Reference

Starkad and Poseidon: New Hash Functions for Zero Knowledge Proof Systems

Structs

MerkleTree	The merkle tree will accept up to MERKLE_ARITY * MERKLE_WIDTH leaves.
Poseidon	The Poseidon structure will accept a number of inputs equal to the arity.
Proof	Set of pairs (idx, Hash) to reconstruct the merkle root. For every level of the tree, Required information to reconstruct the merkle root.
Scalar	The Scalar struct holds an integer \(s < 2^{255} \) which represents an element of \(\mathbb Z / \ell\).

Enums

Error

Possible error states for the hashing.

Constants

MERKLE_ARITY	Arity of the merkle tree
MERKLE_WIDTH	Width of the merkle tree

Traits

PoseidonLeaf

The items for the MerkleTree and Poseidon must implement this trait