October 15 – 20 , 2023, Dagstuhl Seminar 23421

Quantum Cryptanalysis


Gorjan Alagic (University of Maryland – College Park, US)
Stacey Jeffery (CWI – Amsterdam, NL)
Maria Naya-Plasencia (INRIA – Paris, FR)
Rainer Steinwandt (University of Alabama in Huntsville, US)

For support, please contact

Christina Schwarz for administrative matters

Marsha Kleinbauer for scientific matters


Located at the crossroad between quantum computing and cryptography, quantum cryptanalysis is the study of quantum attacks against cryptographic solutions. The focus of this Dagstuhl Seminar includes algorithmic insights, as well as software tools that support the quantum cryptanalyst in optimizing resources. We are especially interested in the quantum-resistance of symmetric and asymmetric cryptographic solutions that are deployed or considered for standardization.

This is the 7th in a series of Dagstuhl Seminars on quantum cryptanalysis (following N 11381, N 13371, N 15371, N 17401, N 19421, and N 21421). To pave the road for the next round of post-quantum standardization, which has already been announced, this seminar is expected to have a stronger emphasis on (in particular lattice-based) constructions for post-quantum digital signatures. The symmetric cryptanalysis component of the program addresses the fact that, based on more recent results, lightweight ciphers may be more vulnerable to quantum attacks than originally anticipated. Taking a step back from the parameter-level analysis of very specific standardization candidates, we expect more discussions and presentations on asymptotic insights, complemented by experimental results.

There are two core themes of this Dagstuhl Seminar:

  • quantum-algorithmic innovations to attack various cryptographic building blocks, with an emphasis on digital signatures and block ciphers, and
  • computational problems that enable the construction of post-quantum cryptographic schemes.

In view of the fast-paced research in quantum cryptanalysis and to make effective use of the opportunities that Schloss Dagstuhl offers, we plan to determine the exact technical focus 2-3 months before the seminar based on feedback from the seminar participants. We plan for a small number of working groups that can spend a substantial part of the week on a specific problem domain within quantum cryptanalysis. The seminar schedule will also ensure regular exchange among the different working groups over the course of the week.

Currently anticipated focus areas include computational problems in lattices and symmetric quantum cryptanalysis beyond quadratic speed-ups, but participants may opt for alternate topics. A key goal is to maintain a strong seminar character, and not be confined to traditional presentations of completed results. As in prior editions, this seminar brings together researchers from academia, government, and industry, including experts from quantum computing and experts in classical cryptography, as well as members of the new generation of native quantum cryptanalysts who are fluent in both disciplines.

Motivation text license
  Creative Commons BY 4.0
  Gorjan Alagic, Stacey Jeffery, Maria Naya-Plasencia, and Rainer Steinwandt

Dagstuhl Seminar Series


  • Cryptography And Security
  • Data Structures And Algorithms
  • Emerging Technologies


  • Cryptanalysis
  • Post-quantum cryptography
  • Quantum algorithms
  • Quantum resource estimation
  • Computational algebra


In the series Dagstuhl Reports each Dagstuhl Seminar and Dagstuhl Perspectives Workshop is documented. The seminar organizers, in cooperation with the collector, prepare a report that includes contributions from the participants' talks together with a summary of the seminar.


Download overview leaflet (PDF).

Dagstuhl's Impact

Please inform us when a publication was published as a result from your seminar. These publications are listed in the category Dagstuhl's Impact and are presented on a special shelf on the ground floor of the library.


Furthermore, a comprehensive peer-reviewed collection of research papers can be published in the series Dagstuhl Follow-Ups.