Faculty at CISPA Helmholtz Center for Information Security


zksk (Zero-knowledge Swiss Knife) is a library for easily defining and computing zero-knowledge proofs. Developers define proofs using a simple yet powerful Python DSL that resembles Camenisch-Stadler notation that is often used in academic publications. Moreover, zksk defines higher level zero-knowledge building blocks such as range proofs, and proofs of signatures.

Code: https://github.com/spring-epfl/zksk/

Documentation: https://zksk.readthedocs.io

zksk: A Library for Composable Zero-Knowledge Proofs
Wouter Lueks, Bogdan Kulynych, Jules Fasquelle, Simon Le Bail-Collet, and Carmela Troncoso
Proceedings of the 18th ACM Workshop on Privacy in the Electronic Society, WPES, London, UK, 2019, pp. 50–54.


Lightnion is a Javascript anonymous communication library that provides anonymous communication for web applications, providing seamless anonymity for users. It uses the existing Tor network. The library provides a convenient interface to make anonymous GET/POST requests to facilitate easy integration.

Lightnion consists of a browser-side Javascript Tor client and a proxy that facilitates communication between browsers and the Tor network.

Code: https://github.com/spring-epfl/lightnion/

Lightnion: seamless anonymous communication from any web browser
Wouter Lueks, Matthieu Daumas, and Carmela Troncoso
Workshop on Measurements, Attacks and Defenses for the Web (MADWeb) 2019, 2019.


While I was a PhD student in Nijmegen, The Netherlands, I worked extensively on IRMA. A system designed to provide easy-to-use attribute-based credentials to users and organizations. I helped develop and design large parts of the initial IRMA Android smartphone application and frontend and backend. Since then, the team has continue to improve the application, including supporting iOS and moving to a different cryptographic backend. See here for the latest work.

IRMA: practical, decentralized and privacy-friendly identity management using smartphones
Gergely Alpár, Fabian van der Broek, Brinda Hampiholi, Bart Jacobs, Wouter Lueks, and Sietse Ringers
HotPETS 2017, Minneapolis. 2017.

Percy++ PIR library

At the University of Waterloo I worked on speeding up information-theoretic private information retrieval. When the server processes queries in batches, it can do faster than if it were to processes the queries one by one. We integrated these improvements into the Percy++ library

Sublinear Scaling for Multi-Client Private Information Retrieval
Wouter Lueks and Ian Goldberg
Financial Cryptography and Data Security - 19th International Conference, FC 2015, San Juan, Puerto Rico, January 26-30, 2015, Revised Selected Papers, 2015, pp. 168–186.