Welcome
to the webpages of the "Codes and Cryptography" research group. In the research group, we develop and investigate cryptographic methods, especially for the protection of privacy. Our interests and works range from the complexity-theoretical and algorithmic foundations of cryptographic techniques to the design and proof of the security of cryptographic primitives and to the efficient implementation of these primitives. The focus is on lattice-based primitives and rationally secure primitives. Lattice-based methods use methods from the (algorithmic) geometry of numbers and are considered promising candidates for methods that resist attacks from quantum computers, i.e. are post-quantum secure. While cryptography usually considers malicious attackers, rationally secure cryptography studies methods that are secure against selfish attackers, where selfishness is defined in terms of game theory.
Research
Current research foci
- Lattice-based privacy-preserving cryptography
- Multi-party computation and rational cryptography
- (Quantum-) Complexity of lattice problems
Our research page provides more details on current as well as former projects and research foci.
Teaching
On the teaching page we inform you about our lectures and seminars, list open topics for theses, provide templates for presentations and theses, and offer a FAQ for seminars.
Publications
Use one of the following links to access an overview of our relevant publications:
- All publications: Open list in Research Information System or on our page of publications.
- Dissertations: Open list in Research Information System or on our page of dissertations.
- Complete Diploma-/Master's theses: Open list in Research Information System.
- Completed Bachelor's theses: Open list in Research Information System.
Contact

Prof. Dr. Johannes Blömer
Codes and Cryptography
Pohlweg 51
33098 Paderborn
Office hours
Do, 11:00-12:00