Bochum Challenges


The purpose of our Bochum Challenges is to encourage cryptanalysis of medium-sized instances of post-quantum schemes, in order to get more confidence in the reliability of current security estimates.

We explicitly focus on feasible challenge parameter sets to stimulate real-world cryptanalysis research in this field. We start our project with challenges for the lattice-based NIST encryption standard Kyber, but will regularly enhance our challenges with down-scaled parameter sets for cryptographic schemes of real world significance.

Although we consider a parameter set solved when you recover its secret key, for the fun of cryptanalysis we strongly encourage you to also decode our challenge ciphertext into a (meaningful) message.


2023-06-27 Kyber Challenges


You can use the following BibTeX snippet to cite and refer to this page:

  title = {Bochum Challenges},
  author = {The {Bochum Challenges} Team},
  url = {},
  note = {Available at \url{}},
  year = 2024,
  month = jul,