Research interests Pure mathematics. Selection principles: applications of infinite-combinatorial methods in general and set theoretic topology, with emphasis on questions in real analysis (special subsets of the real line; function spaces); Topological additive combinatorics and Ramsey theory; Pontryagin-van Kampen duality, via set theoretic and topological methods. Computational mathematics. Combinatorial and computational group theory motivated by cryptography (noncommutative algebraic cryptology), with emphasis on public key cryptography.