0.0.0-alpha.2 • Public • Published


The OPAQUE asymmetric password-authenticated key exchange protocol library (libopaque) compiled to WebAssembly and pure JavaScript using Emscripten.


libopaque implements the OPAQUE protocol as proposed by the Internet Engineering Task Force (IETF) Crypto Forum Research Group (CFRG).

The OPAQUE protocol is a secure asymmetric password-authenticated key exchange (aPAKE) that supports mutual authentication in a client-server setting without reliance on PKI and with security against pre-computation attacks upon server compromise. In addition, the protocol provides forward secrecy and the ability to hide the password from the server, even during password registration.


The dist directory contains pre-built scripts. Copy one of the files to your application:

  • libopaque.js is a minified single-file script that you can include in webpages.
  • libopaque.debug.js is a non-minified version of libopaque.js useful for debugging.

libopaque.js is also available on npm: libopaque.


On the server side, see demo/app.js for example usage.

On the client side, see demo/public/index.js and demo/public/index-worker.js for example usage.

Running the Demo

If you have Node.js installed, here is how to run the demo:

$ # cd to this directory.
$ cd demo
$ npm install
$ node app.js
$ # Navigate to http://localhost:8080 in a browser.
$ # Type Ctrl+C to terminate.

Here is how to run the demo using Docker:

$ # cd to this directory.
$ docker run -it --publish 8080:8080 --rm \
  --name libopaque-demo \
  --user node \
  --volume "$(pwd)/..":/home/node/src \
  --workdir /home/node/src/js/demo \
  creemama/node-no-yarn:lts-alpine \
  sh -c 'npm install && node app.js'
$ # Navigate to http://localhost:8080 in a browser.
$ docker stop libopaque-demo


If you want to compile the files yourself, you need the following dependencies installed on your system:

  • Emscripten
  • binaryen
  • git
  • NodeJS
  • make

Running make will make dist\libopaque.js and dist\libopaque.debug.js. The following is an example build using Docker:

$ # cd to this directory.
$ docker run -it --rm \
  --volume "$(pwd)/..":/src \
  --workdir /src/js \
  emscripten/emsdk:1.40.1 \
  bash -c 'apt update && apt install pkgconf uncrustify && make'

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npm i libopaque

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  • creemama
  • opaque_maintainer