Struct MimcHasher 

pub struct MimcHasher { /* private fields */ }

MiMC-Feistel sponge hasher.

This struct provides the MiMC hash function with configurable parameters. For most use cases, use MimcHasher::default() which provides parameters compatible with Tornado Cash / circomlib.

Example

use stealth_lib::hash::MimcHasher;

// Use default parameters (compatible with Tornado Cash)
let hasher = MimcHasher::default();
let hash = hasher.hash(123, 456);

// Hash is deterministic
assert_eq!(hasher.hash(123, 456), hasher.hash(123, 456));

// Different inputs produce different outputs
assert_ne!(hasher.hash(123, 456), hasher.hash(123, 789));

Implementations

impl MimcHasher

pub fn new(field_prime: u128, num_rounds: usize, constants: Vec<u128>) -> Self

Creates a new MimcHasher with custom parameters.

Arguments

• field_prime - The field modulus for arithmetic operations
• num_rounds - Number of Feistel rounds
• constants - Round constants (must have at least num_rounds * 2 elements)

Example

use stealth_lib::hash::MimcHasher;

let constants = vec![0u128; 20];
let hasher = MimcHasher::new(
    340282366920938463463374607431768211455, // 2^128 - 1
    10,
    constants,
);

pub fn field_prime(&self) -> u128

Returns the field prime used by this hasher.

pub fn num_rounds(&self) -> usize

Returns the number of rounds used by this hasher.

pub fn hash(&self, left: u128, right: u128) -> u128

MiMC sponge hash function.

Computes the MiMC-Feistel-Sponge hash of two input values. This is the primary hash function used for Merkle tree construction.

Arguments

• left - First input value
• right - Second input value

Returns

The hash output as a u128.

Example

use stealth_lib::hash::MimcHasher;

let hasher = MimcHasher::default();

// Hash two values
let hash = hasher.hash(123, 456);

// Hash is deterministic
assert_eq!(hash, hasher.hash(123, 456));

pub fn mimc_sponge(&self, left: u128, right: u128, key: u128) -> u128

MiMC sponge with explicit key parameter.

Lower-level function that allows specifying a custom key. Most users should use hash instead.

Arguments

• left - First input value
• right - Second input value
• key - Sponge key

Returns

The hash output as a u128.

pub fn hash_single(&self, input: u128) -> u128

Hash a single value.

Convenience method to hash a single input by pairing it with zero.

Arguments

• input - The value to hash

Returns

The hash output as a u128.

Example

use stealth_lib::hash::MimcHasher;

let hasher = MimcHasher::default();
let hash = hasher.hash_single(12345);

Trait Implementations

impl Clone for MimcHasher

fn clone(&self) -> MimcHasher

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for MimcHasher

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for MimcHasher

fn default() -> Self

Creates a MimcHasher with default parameters compatible with Tornado Cash.

• Field prime: 2^128 - 1
• Rounds: 10
• Constants: circomlib-compatible