MP-PSI

The package contains the APIs to build a multi party private set intersection web-app. Note that the package is not compatible with a node environment.

PSI stands for Private Set Intersection. It allows two parties to compute the intersection of their sets without revealing anything else about their sets.

BFV is a fully homomorphic encryption scheme. It allows to perform addition and multiplication on encrypted data. The PSI protocol made available in this library uses the BFV scheme to perform the encryption of the sets, compute the intersection and decrypt the result. In particular, the multiparty protocol is based on the paper Mouchet, Christian, et al. "Multiparty homomorphic encryption from ring-learning-with-errors.".

The source code for the npm package is available at https://github.com/gaussian-dev/MP-PSI/tree/main/pkg

Security Notice

This is a research project and is not meant to be used in production. The code has not been audited.

Install

Install the mp-psi package with npm:

npm i mp-psi

or yarn:

yarn add mp-psi

Usage in web-app

import init, { state0_bindgen, state1_bindgen, state2_bindgen, state3_bindgen, state4_bindgen } from "mp-psi";

init().then(() => {
const state0 = state0_bindgen();        
const bit_vector_a = [0, 1, 0, 0, 1, 0, 1, 0, 1, 1];
const state1 = state1_bindgen(state0.message_a_to_b, bit_vector_a);
const bit_vector_b = [1, 1, 1, 1, 1, 0, 1, 0, 0, 0];
const state2 = state2_bindgen(state0.private_output_a, state0.public_output_a, state1.message_b_to_a, bit_vector_b);
const state3 = state3_bindgen(state1.private_output_b, state1.public_output_b, state2.message_a_to_b);
const psi_output_a = state4_bindgen(state2.public_output_a, state3.message_b_to_a);
const psi_output_b = state3.psi_output;
});

A web-app example is available inside the pkg/index.html file here. You can test it by:

• Cloning the repo
• Serving the pkg directory with a local web server, (e.g. python3 -m http.server)
• Visit http://localhost:8000 in your browser
• Open the console. It will show you the result of the PSI protocol.