Multi-party computation protocol

End-to-end encrypted relay service designed for MPC/TSS applications built using the noise protocol and websockets for the transport layer.

The service facilitates secure communication between peers but it does not handle public key exchange nor meeting points.

For clients to use the relay service they must know the public key of the server and the public keys of all the participants for a session.

Creating a meeting point that shares the session identifier between participants to execute an MPC/TSS protocol is left up to the application. Typically, this can be achieved by encoding the session identifier in a URL and sharing the URL with all the participants.

Server Installation

cargo install mpc-relay

Documentation

• protocol Message types and encoding
• server Websocket server library
• client Websocket client library
• cli Command line interface for the server

The client implementation uses web-sys for webassembly and tokio-tungstenite for other platforms.

Development

Getting Started

You will need the rust toolchain and a few other tools:

cargo install cargo-make
cargo install wasm-pack

Minimum supported rust version (MSRV) is 1.68.1.

Run the gen-keys task to setup keypairs for the server and test specs:

cargo make gen-keys

Server

Start a server:

cargo run -- start config.toml

Documentation

cargo make doc

Tests

Native Platform

To run the tests using the native client:

cargo make test

Web Platform

To test the web client using webassembly, first start a test server (port 8008):

cargo make test-server

Now you can run the webassembly tests:

cargo make test-wasm

End-to-end tests

The webassembly tests cannot simulate key generation and signing as it is too computationally intensive for a single-threaded context and the integration tests would hit the browser script timeout before completion.

To run end to end tests for the web platform, first compile the webassembly bindings:

cargo make bindings

Then generate the test files:

cargo make gen-e2e

Start a server for the end-to-end tests:

cargo make e2e-server

Note we don't use the test-server task as the e2e tests use a configuration with different timeout settings.

Then start a dev server (port 9009) used to serve the HTML and Javascript:

cargo make dev-server

Running the test specs requires playwright, so first install the dependencies for the end-to-end tests and then the playwright browsers:

cd tests/e2e
npm install
npx playwright install

Then you should be able to run the end-to-end tests:

npm test

Or run headed to see the browsers, which can be useful for debugging:

npm run test-headed

Or use the playwright UI:

npm run test-ui

If you need to debug the test specs you can also just open the pages manually in a browser, first open the initiator /gg20/p1.html and then open the participant pages /gg20/p2.html and /gg20/p3.html on the http://localhost:9009 development server.

License

The bindings and driver crates are released under the GPLv3 license and all other code is either MIT or Apache-2.0.

lib.rs:

Relay service websocket client using the noise protocol for end-to-end encryption intended for multi-party computation and threshold signature applications.

To support the web platform this client library uses web-sys when compiling for webassembly otherwise tokio-tunsgtenite.