Semacaulk

Semacaulk is a custom prover and verifier of set membership proofs which uses an on-chain polynomial commitment to enable cheap insertions, and techniques which make verification no more expensive than verifying a Groth16 proof.

For more information, please refer to this document. More documentation will be written and released soon.

Quick start

1. Install Rust using these instructions.

2. Install Foundry using these instructions.

3. Clone this repository.

git clone https://github.com/geometryresearch/semacaulk.git && \
cd semacaulk

4. Build the contracts

./build_contracts.sh

5. Run tests

cargo test

Documentation

We use mdbook v0.4.25 for documentation.

Install mdbook using these instructions.

To build the Semacaulk documentation, run this in the Semacaulk project root:

mdbook serve ./docs

Demo

The Powers of Tau output from Hermez Network (11.ptau) is already in the repository. To run a demo of Semacaulk with a maximum capacity of 2 ^ 11 = 2048, first build the demo executable:

cargo build --release

Run the demo:

./target/release/demo 11 11.ptau

To run a demo with a different maximum capacity, download a larger .ptau file and specify the log 2 of the desired maximum capacity:

./target/release/setup 12 12.hex lagrangeComms_12

Now, run:

./target/release/demo 12 12.hex lagrangeComms_12

A future release will integrate implement the functionality of export-ptau-points into the setup executable, so a separate step will not be needed.

CLI client

For testing and demonstration purposes, we also include a CLI client binary.

To deploy a Semacaulk contract (supporting a capacity of 2 ^ 11), first run anvil or any Ethereum node at 127.0.0.1:8545 or use the --rpc flag to specify a node.

Make sure you have built the client binary:

./build_contracts.sh && \
cargo build --release --bin client

Run the client deploy subcommand. Make sure that the -l flag is set to the correct value!

./target/release/client deploy --ptau ./11.ptau --rpc http://127.0.0.1:8545 -l 11

The contract address will be printed to the console. With the default private key on a fresh RPC node, the address should be 0x5fbdb2315678afecb367f032d93f642f64180aa3.

To insert an identity commitment (where the identity nullifier is 1 and the identity trapdoor is 2, run client insert:

./target/release/client insert --ptau 11.ptau -c 0x5fbdb2315678afecb367f032d93f642f64180aa3 --rpc http://127.0.0.1:8545 -n 0x1 -t 0x2 -l 11

The client will print the transaction hash and the index of the insertion.

Transaction hash:
0x634bfbfd1984fd27205c2995860572703d8f2b92face4cf7b827e70f33009617
Identity index:
0x0000000000000000000000000000000000000000000000000000000000000000

Documentation

We use mdbook v0.4.25 for documentation To build the documentation, navigate to the docs directory and run:

mdbook serve