zkbk

zkbk is a collection of zero-knowledge gadgets built on top of the arkworks ecosystem to facilitate first person credentials. The crate packages reusable primitives—Merkle trees, vector commitments, polynomial utilities, pseudorandom functions, random oracles, and Schnorr signatures—together with circuit-friendly constraint gadgets and end-to-end Groth16 integration tests.

Getting Started

1. Install Rust (recommended via rustup) and ensure the stable toolchain is active.
2. Fetch dependencies and compile the library:

   cargo build

3. Generate docs if desired:

   cargo doc --open

Repository Layout

• src/lib.rs – Crate entry point exporting all modules.
• src/merkle_tree/ – Layered hash configuration trait, path verification, and fixed-height Merkle tree implementation.
• src/vector_commitment/bytes/ – Vector commitment interface for byte-array elements.
• src/record_commitment/ – Commitment schemes (Pedersen, KZG, SHA-256) with circuit gadgets for record construction.
• src/prf/ – JZ PRF abstraction backed by configurable CRHs plus constraint system gadgets.
• src/random_oracle/ – Random oracle trait and a Blake2s-backed implementation for both native and R1CS contexts.
• src/signature/ – Signature trait with a Schnorr implementation over JubJub, including verification gadgets.
• src/utils.rs – Helpers for serialization, bit conversion, and polynomial/domain utilities used across modules.
• tests/ – Heavyweight integration tests that compose the primitives into Groth16 circuits (e.g., nullifier PRFs, Pedersen commitments, and membership checks). Design diagrams supporting several tests live under tests/designs/.

Running Tests

The project includes both unit tests and integration tests that synthesize and verify Groth16 proofs. On most machines you will want to enable optimizations:

cargo test --release

Contributing & License

Contributions are welcome; please open an issue or pull request with ideas or fixes. The project is licensed under the Apache License, Version 2.0. See LICENSE for details.