The project aims at studying properties of hash and trapdoor functions that are motivated by practical applications and are implicitly held by the random oracles or easy to realize in the idealistic random oracle model. But, are not well-defined and/or not known to be realizable in the standard model. In particular, the research studies non-malleable hash functions and (possibly trapdoor) functions that hide partial information. The project investigates the new appropriate notions of security for these primitives and seeks constructions that probably meet the security definitions. The outcome of the proposed research should help understanding of the gap between the standard and the random oracle model, and give more confidence in security of the practical schemes. Studying new security properties is timely, given NIST's ongoing cryptographic hash algorithm competition. An integral part of the project is continuing quality education on all aspects of modern cryptography.
