An Algebraic Characterization of Security of Cryptographic Protocols

Abstract: Several of the basic cryptographic constructs have associated algebraic structures. Formal models proposed by Dolev and Yao to study the (unconditional) security of public key protocols form a group. The security of some types of protocols can be neatly formulated in this algebraic setting. We investigate classes of two-party protocols. We then consider extension of the formal algebraic framework to private-key protocols. We also discuss concrete realization of the formal models. In this case, we propose a definition in terms of pseudo-free groups.