Many cryptographic protocols and attacks on these protocols make use of the fact that the order in which encryption is performed does not affect the result of the encryption, i.e., encryption is commutative. However, most models for the automatic analysis of cryptographic protocols can not handle such encryption functions since in these models the message space is considered a free term algebra...

We introduce knowledge flow analysis, a simple and flexible formalism for checking cryptographic protocols. Knowledge flows provide a uniform language for expressing the actions of principals, assumptions about intruders, and the properties of cryptographic primitives. Our approach enables a generalized two-phase analysis: we extend the two-phase theory by identifying the necessary and sufficie...

We propose the study of quasi-cryptographic primitives and protocols. These are relaxed versions of standard cryptographic primitives and protocols where the adversary may be given more resources than some of the honest parties. The purpose of this study is to obtain a better understanding of some of the obstacles in basing cryptography on NP-hardness, as well as the relations between various c...

Much work has been done in recent decades to apply sophisticated cryptographic techniques to achieve strong end-to-end verifiability in election protocols. The properties of these protocols are much stronger than in any system in general use; however, the complexity of these systems has retarded their adoption. This paper describes a relatively simple but still effective approach to cryptograph...

Most of cryptographic protocols are subjects to very subtle attacks. Therefore, many researchers have developed tools to model and analyze protocols to guarantee their security properties. The spi calculus has proved to be useful for analyzing and reasoning on cryptographic protocols. However, current works assumed that the spi calculus dealt with transferring a single unstructured message for ...