JIGG

JavaScript implementation of garbled gates and 2PC boolean circuit protocols

Installation and Setup

The entirety of this project is written in JavaScript. Running the server requires Node.js, npm (both installed via yum install nodejs npm or brew install npm on macOS), and Socket.IO and libsodium.

Run npm to install all JIGG dependencies:

npm install

Running the Prototype

As a Server

Start the server from server.js with the command below and optionally specify a port number such as:

node server 3000

As a Party

Parties can go to http://localhost:port/ in a web browser supporting JavaScript to begin communications. This is strictly a 2-party protocol at the moment.

Demos

The current circuit in lib/base.js is a 64-bit Equal-to-Zero test (circuits/zero_equal.txt) and several other circuits from the same page. Circuits larger than ~6000 gates seem to hang the JS engine (sometimes only temporarily) and so are now forced to run in sequence to prevent this from occurring.

There is now a SHA-256 demo at sha256.html and client.html. The boolean circuit for SHA has +100,000 gates, and by limiting the number of gates encrypted in parallel, JIGG is able to compute it in 4-5 minutes in the browser. Test vectors are found here.

Circuit Format

JIGG can evaluate a boolean circuit in either of the following formats:

In JavaScript as a circuit object

const circuit = {
  wires: 8, gates: 4,
  input: [1, 2, 3, 4], output: [5, 7, 8],
  gate: [
    {wirein: [1,2], wireout: 5, type: 'and'},
    {wirein: [3,4], wireout: 6, type: 'xor'},
    {wirein: [6], wireout: 7, type: 'not'},
    {wirein: [5,7], wireout: 8, type: 'and'}
  ]
};

As a circuit in the standardized 'Bristol Format' which is supported by several compiled MPC libraries such as SHARE-MAMBA.

4 8
1 4
1 3
2 1 0 1 4 AND
2 1 2 3 5 XOR
1 1 5 6 INV
2 1 4 6 7 AND

Capabilities

JIGG is designed for semi-honest parties. We support point-and-permute, free-XOR, free single-input gates, encryption from a random oracle (fixed-key XChaCha20). The half-AND optimization is compatible but not yet supported. The default label size is 128 bits and relies on JavaScript's Uint8Array class. The simple-labels branch demonstrates dynamically-sized labels ≤53 bits without using arrays. Some potential improvements are listed below.

To Do

Change the current oblivious transfer to use ECC from libsodium
Encrypt communications between parties
Half AND gate optimization

wyatt-howe/jigg