News

  • We are looking for (student) teaching assistants for the Discrete Math lecture in Autumn 2025. If you are interested, please contact Roman Langrehr (roman.langrehr@inf.ethz.ch).
  • Karen Azari and Andreas Ellison got a paper accepted at ACNS 2025. Congratulations!
  • Dennis Hofheinz and Roman Langrehr got a paper accepted at PKC 2025. Congratulations!
  • Karen Azari and Dennis Hofheinz got a paper accepted at PKC 2025. Congratulations!
  • Marian Dietz got a paper accepted at EUROCRYPT 2025. Congratulations!
  • Dennis Hofheinz and Roman Langrehr got a paper accepted at EUROCRYPT 2025. Congratulations!
  • Karen Azari got a paper accepted at EUROCRYPT 2025. Congratulations!
  • Cecilia Boschini got a paper accepted at the IEEE Symposium on Security and Privacy 2025. Congratulations!
  • Karen Klein got a paper accepted at SCN 2024. Congratulations!
  • Roman Langrehr got a paper accepted at TCC 2024. Congratulations!
  • Milan Gonzalez-Thauvin is visiting from 07.09.2024-07.02.2025 Welcome Milan!
  • Michael Klooss and Michael Reichle got a paper accepted at ASIACRYPT 2024. Congratulations!
  • Michael Klooss got a paper accepted at ASIACRYPT 2024. Congratulations!
  • Nicholas Brandt got a paper accepted at TCC 2024. Congratulations!
  • Michael Reichle got a paper accepted at CRYPTO 2024. Congratulations!
  • Cecilia Boschini got a paper accepted at CRYPTO 2024. Congratulations!
  • Julia Kastner and Michael Reichle got a paper accepted at CRYPTO 2024. Congratulations!
  • Michael Reichle got a paper accepted at PKC 2024. Congratulations!
  • Dennis Hofheinz, Kristina Hostáková, Roman Langrehr, and Bogdan Ursu got a paper accepted at PKC 2024. Congratulations!
  • Dennis Hofheinz, Kristina Hostáková, Julia Kastner, Karen Klein, and Akin Ünal got a paper accepted at PKC 2024. Congratulations!
  • Roman Langrehr got a paper accepted at TCC 2023. Congratulations!
  • Sebastian Faller and Kristina Hostáková got a paper accepted at ASIACRYPT 2023. Congratulations!
  • Julia Kastner got a paper accepted at ACM CCS 2023. Congratulations!
  • Michael Klooß is visiting from 7.08.-11.08. Welcome Michael!
  • Thomas Attema is visiting from 10.07.-11.08. Welcome Thomas!
  • Adam O'Neill and Ojaswi Acharya are visiting from 30.05.-3.06. Welcome Adam and Ojaswi!
  • The Information Security lecture (co-held with the Information Security Group) was awarded the VIS Teaching Award for Best Interaction. Congratulations!
  • Sebastian Faller got a paper accepted at CRYPTO 2023. Congratulations!
  • Dennis Hofheinz, Julia Kastner, and Karen Klein got a paper accepted at CRYPTO 2023. Congratulations!
  • Akin Ünal won the Early Career Best Paper Award at EUROCRYPT 2023 with his paper "Worst-Case Subexponential Attacks on PRGs of Constant Degree or Constant Locality". Congratulations Akin!
  • Bogdan Ursu graduated with his thesis titled "New Constructions of Round-Efficient Zero-Knowledge Proofs". Congratulations Bogdan!
  • Dennis Hofheinz got a paper accepted at PKC 2023. Congratulations!
  • Dennis Hofheinz and Suvradip Chakraborty got a paper accepted at EUROCRYPT 2023. Congratulations!
  • Suvradip Chakraborty got a paper accepted at EUROCRYPT 2023. Congratulations!
  • Akin Ünal got a paper accepted at EUROCRYPT 2023. Congratulations!
  • Nicholas Brandt got a paper accepted at Financial Crypto 2023. Congratulations!
  • Michael Reichle is visiting from 12.12.-15.12. Welcome Michael!
  • Erkan Tairi is visiting from 28.11.-2.12. Welcome Erkan!
  • 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

    Professor

    Administration

    PostDocs

    PhD Students

    Alumni

    Research

    Motivation.

    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.

    Goal.

    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).

    Teaching

    Lecture: Digital Signatures

    This information concerns the “Digital Signatures” lecture in the Spring 2024 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 2024 semester at ETH. The content for this course will be provided through Moodle.

    Seminar: Current Topics in Cryptography

    Information about the course will be communicate to the subscribed participants via email.

    Lecture: Discrete Math

    Starting with the autumn semester 2025, the Discrete Math lecture will be held by Prof. Hofheinz. If you are interested in becoming a student/teaching assistant, please contact Roman Langrehr (roman.langrehr@inf.ethz.ch).

    Available Theses

    For more details or questions in general please contact michael.reichle@inf.ethz.ch.
    Improving the Security of Lattice-based Threshold Signatures(Master Thesis)

    A t-out-of-N threshold signature distributes a secret key among N parties, such that any group of at least t parties can jointly produce a valid siganture. Importantly, even if up to t-1 parties are corrupted, an adversary still cannot forge signatures. Threshold signatures have practical applications, such as blockchain systems. Recently, NIST has launched a standardization effort [1] for multi-party threshold protocols.
    While there are efficient constructions with strong security guarantees in the classical (pre-quantum) settings, research on post-quantum (in particular, lattice-based) threshold signatures remains limited (see e.g. [2]), and many existing constructions provide only weak security guarantees.
    The aim of this project is to enhance the security guarantees of existing lattice-based threshold signatures. In particular, the project will focus on applying existing technique for distributed key generation and for adaptive security to existing lattice-based constructions to enhance their security guarantees. A student interested in this thesis should have a background in crytography (Information Security course, Digital Signature course, etc.) and basic knowledge of mathematics

    Moeto Suzuki
    Foundations of Cryptography Contact
    Universitaetstrasse 6
    CAB Building, H Floor
    8092 Zurich
    Switzerland
    claudia.guenthart@inf.ethz.ch foc.ethz.ch