Cryptography is both a fascinating mathematical science and a key technology for the emerging information society, with theory and applications being closely related. This article reviews some highlights of the past ten years of research in cryptography and its applications and discusses some of the main challenges for future research.
A major future research theme is to weaken the assumptions on which security proofs are based, in particular computational intractability assumptions, trust assumptions, and physical assumptions. These assumptions must be made explicit. Computation and communication are physical processes rather than mathematically idealized objects, involving for example quantum phenomena. This fact could have a profound impact on cryptographic research and implementations.