Cairo Bulletproofs

Bulletproofs are a zero knowledge proof system which allow for short inner product, range, shuffle, and arithmetic circuit proofs. Bulletproofs also support faster MPC protocols.

This repo implements the inner product proofs (protocol 2) but can be extended to range, shuffle, and arithmetic circuit proofs.

Getting Started

Before doing anything, make sure you are on Python version 3.10 or above.

1. Make sure to install Cairo and install Protostar. Make sure that your Cairo version is at last v0.9.0.
2. Clone the repo with recursed submodules:

git clone https://github.com/Lev-Stambler/bulletproof-cairo --recurse-submodules && cd bulletproof-cairo

3. Source the cairo environment: source ~/cairo_venv/bin/activate
4. Install the Python requirements

cd python_bulletproofs/ && pip install -r requirements.txt

Running a test of the inner product proof

To run a simple set of innerproduct tests, run

./scripts/simple_innerproduct.sh

Using Innerproduct proofs

In order to integrate an innerproduct proof with your Cairo code, you need to create and set the transcript and proof via a hint and then verify the proof by calling

verify_innerproduct_2(gs, hs, u[0], P[0], proof_innerprod_2, transcript)

where gs, gs, u, P, proof_innerprod_2, and transcript are set with

g = [elliptic_hash(str(i).encode() + seeds[0], CURVE) for i in range(N)]
h = [elliptic_hash(str(i).encode() + seeds[1], CURVE) for i in range(N)]
u = elliptic_hash(seeds[2], CURVE)

a = [<Your first vector of size N>]
b = [<Your second vecotr of size N>]
# Commitment to the innerproduct of a and b
P = vector_commitment(g, h, a, b) + inner_product(a, b) * u

Prov = FastNIProver2(g, h, u, P, a, b, CURVE, prime=p)
proof = Prov.prove() 
# Convert the proof into a cairo format
proof.convert_to_cairo(ids, memory, segments, len(g))

for more details, see ./tests/test_innerproduct.cairo

Next steps

• Add Protostar tests once the ec_point builtin is fully supported by Protostar and Starknet
• Integrate with the Cleopatra VM
• Add range proofs

Contact me

To reach me with questions, find me at levsadev@gmail.com

Disclaimer

This codebase is experimental in nature and not production ready/ safe. The codebase should not be used in production contracts without further review, tests, and updates.