Crate stealth_lib 

stealth-lib

ZK-friendly cryptographic primitives for Rust.

This library provides cryptographic primitives designed for use in zero-knowledge proof systems like Tornado Cash, Semaphore, and similar applications.

Features

• MiMC Hash: Efficient hash function designed for ZK circuits
• Merkle Tree: MiMC-based tree with proof generation and verification
• No unsafe code: #![deny(unsafe_code)]
• no_std support: Optional, for WASM/embedded targets

Quick Start

use stealth_lib::{MerkleTree, MerkleProof};

// Create a Merkle tree with 20 levels (can hold ~1M leaves)
let mut tree = MerkleTree::new(20).unwrap();

// Insert some leaves
let idx = tree.insert(12345).unwrap();

// Generate and verify a proof
let proof = tree.prove(idx).unwrap();
let root = tree.root().unwrap();
assert!(proof.verify(root, &tree.hasher()));

Security Model

Designed for: Zero-knowledge proof circuits (Tornado Cash, Semaphore, etc.)

Guarantees:

• Collision resistance of MiMC (computational)
• Correct Merkle proofs for membership verification

Non-Goals / Explicit Exclusions:

• ❌ Constant-time execution (vulnerable to timing side-channels)
• ❌ General-purpose cryptographic primitives
• ❌ Professional security audit (pending)

For general-purpose cryptography, use established crates like ring, sha2, ed25519-dalek, etc.

Feature Flags

Feature	Default	Description
std	✅	Enable standard library support
serde	❌	Enable serde serialization
borsh	❌	Enable borsh serialization
experimental	❌	⚠️ Educational code only, NOT for production

Re-exports

pub use error::Error;

pub use error::Result;

pub use hash::MimcHasher;

pub use merkle::MerkleProof;

pub use merkle::MerkleTree;

Modules

encoding

Encoding utilities.

error

Error types for stealth-lib operations.

hash

Hash functions for stealth-lib.

hasherDeprecated

Legacy hasher module for backwards compatibility.

merkle

Merkle tree implementation with MiMC hash.

merkle_treeDeprecated

Legacy Merkle tree module for backwards compatibility.

utilsDeprecated

Legacy utilities module for backwards compatibility.

Type Aliases

SolanaErrorDeprecated