eprintid: 342 rev_number: 9 eprint_status: archive userid: 32 dir: disk0/00/00/03/42 datestamp: 2011-06-09 10:03:21 lastmod: 2011-07-11 14:36:26 status_changed: 2011-06-09 10:03:21 type: book_section metadata_visibility: show item_issues_count: 0 creators_name: Boreale, Michele creators_name: De Nicola, Rocco creators_name: Pugliese, Rosario creators_id: creators_id: r.denicola@imtlucca.it creators_id: title: Proof Techniques for Cryptographic Processes ispublished: pub subjects: QA75 divisions: CSA full_text_status: none keywords: Logical aspects of protocol security, Formal methods, Concurrency, Semantics abstract: Contextual equivalences for cryptographic process calculi can be used to reason about correctness of protocols, but their definition suffers from quantification over all possible contexts.Here, we focus on two such equivalences, may-testing and barbed equivalence, and investigate tractable proof methods for them. To this aim, we develop an `environment-sensitive' labelled transition system, where transitions are constrained by the knowledge the environment has of names and keys.On top of the new transition system, a trace equivalence and a co-inductive weak bisimulation equivalence are defined, both of which avoid quantification over contexts. Our main results are soundness of trace semantics and of weak bisimulation with respect to may-testing and barbed equivalence, respectively.This leads to more direct proof methods for equivalence checking. The use of such methods is illustrated via a few examples concerning implementation of secure channels by means of encrypted public channels. We also consider a variant of the labelled transition system that gives completeness, but is less handy to use. date: 1999 date_type: published publisher: IEEE Computer Society pagerange: 157-166 id_number: 10.1109/LICS.1999.782608 refereed: TRUE book_title: Proc. of the 14th IEEE Symposium Logic In Computer Science (LICS'99) official_url: http://doi.ieeecomputersociety.org/10.1109/LICS.1999.782608 citation: Boreale, Michele and De Nicola, Rocco and Pugliese, Rosario Proof Techniques for Cryptographic Processes. In: Proc. of the 14th IEEE Symposium Logic In Computer Science (LICS'99). IEEE Computer Society, pp. 157-166. (1999)