We extend the applied pi calculus with state cells, which are used toreason about protocols that store persistent information. Examples are protocolsinvolving databases or hardware modules with internal state. We distinguish be-tween private state cells, which are not available to the attacker, and public statecells, which arise when a private state cell is compromised by the at...

The applied pi calculus is a language for modelling security protocols. It is an extension of the pi calculus, a language for studying concurrency and process interaction. This chapter presents the applied pi calculus in a tutorial style. It describes reachability, correspondence, and observational equivalence properties, with examples showing how to model secrecy, authentication, and privacy a...

We propose an extension of the Applied Pi–calculus by introducing nondeterministic and probabilistic choice operators. The semantics of the resulting model, in which probability and nondeterminism are combined, is given by Segala’s Probabilistic Automata driven by schedulers which resolve the nondeterministic choice among the probability distributions over target states. Notions of static and o...

A symbolic-style proof system is presented to reason about observational equivalence for applied pi-calculus. The proofs of the soundness and completeness of the system rely on a recently developed theory of symbolic bisimulation for applied pi-calculus. The completeness result of the proof system is restricted to the finite fragment of applied pi-calculus which admits finite partition, and it ...

We propose a symbolic semantics for the finite applied pi calculus.The applied pi calculus is a variant of the pi calculus with extensions formodelling cryptographic protocols. By treating inputs symbolically, oursemantics avoids potentially infinite branching of execution trees due toinputs from the environment. Correctness is maintained by associatingwith each process a se...