My research area is complexity-based cryptography, which investigates the relationships among (abstract or concrete) cryptographic problems, such as the security of complex cryptographic protocols built from more fundamental cryptographic primitives. The security proofs for the protocols of the new German identity card are a concrete example of my work.
Central to my research is the question of modeling (what does it mean to be secure?) and the notion of a reduction, originating in complexity theory and nowadays forming the standard technique for conducting security proofs for protocols. I'm interested in both the applications of these notions and the notions themselves as a research topic. This requires close interaction with related areas such as complexity theory, IT security, number theory, or algorithmics.
For a list of publications, please see www.cryptoplexity.de or DBLP. You can also look at my author profile on Google Scholar. Maybe someday I'll also maintain a copy of the publications here.Â