• Christoph Striecks is visiting from 19.9.-23.9. Welcome Christoph!
  • Karen Klein got a paper accepted at ASIACRYPT 2022. Congratulations!
  • Thomas Attema is visiting from 12.9.-16.9. Welcome Thomas!
  • David Niehues is visiting from 5.9.-9.9. Welcome David!
  • Julia Kastner got a paper accepted at ASIACRYPT 2022. Congratulations!
  • Nicholas Brandt, Dennis Hofheinz, Julia Kastner, and Akin Ünal got a paper accepted at TCC 2022. Congratulations!
  • Photograph of the group in front of the CAB building




    PhD Students



    Cryptography is a crucial tool for securing information systems. Cryptographic building blocks ensure the secrecy and integrity of information, and help to protect the privacy of users. Still, most actually deployed cryptographic schemes are not known to have any rigorously proven security guarantees. This has led to a number of far-reaching security issues in widely deployed software systems.


    Our goal is to provide practical cryptographic building blocks that come with rigorously proven security guarantees. These building blocks should be efficient enough for the use in large-scale modern information systems, and their security should be defined and formally analyzed in a mathematically rigorous manner.

    Technical interests.

    We are interested in the foundations of theoretical cryptography, and in general ways to derive constructions and security guarantees in a modular fashion. One research focus in our group concerns new cryptographic building blocks such as indistinguishability obfuscation, functional encryption, and fully homomorphic encryption. We are particularly interested in the design and analysis of cryptographic schemes in the public-key setting. This covers common tools like public-key encryption and digital signatures, specifically in realistic modern scenarios (such as settings with adaptive adversaries, and a huge number of users).


    Lecture: Digital Signatures

    This information concerns the “Digital Signatures” lecture in the Spring 2022 semester at ETH. The content for this course will be provided through Moodle.

    Lecture: Information Security

    This information concerns the “Information Security” lecture in the Spring 2022 semester at ETH. The content for this course will be provided through Moodle.

    Seminar: Current Topics in Cryptography

    You can find the link to the seminar page here.

    Available Theses

    Zero-Knowledge Proofs

    A zero-knowledge proof system is a protocol between a prover and a verifier, where the prover attempts to convince the verifier that a statement x belongs to an NP language. The honest prover possesses a witness w for the fact that x is a valid statement in the language and the zero-knowledge property asks that during the interaction with the verifier, no information is leaked about the witness w. Moreover, a cheating prover should not be able to convince the verifier to accept any statements which are not in the language.

    Zero knowledge protocols have many applications, for example in privacy-preserving authentication or in building other cryptographic protocols.

    In this project, we will look at recent breakthroughs in the field of zero-knowledge and attempt to build on these techniques to obtain new results.

    Bogdan Ursu
    Foundations of Cryptography Contact
    Universitaetstrasse 6
    CAB Building, H Floor
    8092 Zurich