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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