groth16-implementation

Educational Groth16 zk-SNARK implementation over BN254 using arkworks.

This repository implements the full flow:

• R1CS constraint system
• R1CS -> QAP transformation
• Trusted setup (proving + verifying keys)
• Prover
• Verifier (pairing equation)

Current Status

• Core flow is working end-to-end.
• cargo test passes.
• cargo run executes a full Groth16 example for:
  • x^4 + 5x^2y^2 = z

Requirements

• Rust (stable)
• Cargo

Quick Start

Build:

cargo build

Run tests:

cargo test

Run the demo circuit from main.rs:

cargo run

Expected output:

Groth16 proof valid: true

Demo Circuit in main.rs

The default executable proves and verifies:

x^4 + 5x^2y^2 = z

with example values:

• x = 2
• y = 3
• z = 196

It builds R1CS constraints for intermediate wires (x^2, y^2, x^4, 5x^2y^2), runs setup, creates a proof, and verifies it.

Project Structure

src/
  common/      # Curve/field utilities and pairing helpers
  r1cs/        # Constraint representation and dense R1CS matrices
  qap/         # R1CS -> QAP interpolation and target polynomial
  srs/         # Powers of tau utilities
  setup/       # Trusted setup, proving key, verifying key
  prover/      # Groth16 prover
  verifier/    # Groth16 verifier
  proof.rs     # Proof type (A, B, C)
  main.rs      # End-to-end demo example

tests/
  common_tests.rs
  r1cs_tests.rs
  qap_tests.rs
  srs_tests.rs
  setup_tests.rs
  prover_tests.rs
  verifier_tests.rs

Test Components Separately

You can run tests per component:

cargo test --test common_tests
cargo test --test r1cs_tests
cargo test --test qap_tests
cargo test --test srs_tests
cargo test --test setup_tests
cargo test --test prover_tests
cargo test --test verifier_tests

Notes

• This codebase is educational and not production-hardened.
• Trusted setup is generated locally for demonstration.
• No serialization format or persistent parameter storage is included yet.

License

MIT. See LICENSE.