A proof theoretic analysis of intruder theories

Alwen Tiu*, Rajeev Goré

*Corresponding author for this work

    Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

    2 Citations (Scopus)

    Abstract

    We consider the problem of intruder deduction in security protocol analysis: that is, deciding whether a given message M can be deduced from a set of messages F under the theory of blind signatures and arbitrary convergent equational theories modulo associativity and commutativity (AC) of certain binary operators. The traditional formulations of intruder deduction are usually given in natural-deduction-like systems and proving decidability requires significant effort in showing that the rules are "local" in some sense. By using the well-known translation between natural deduction and sequent calculus, we recast the intruder deduction problem as proof search in sequent calculus, in which locality is immediate. Using standard proof theoretic methods, such as permutability of rules and cut elimination, we show that the intruder deduction problem can be reduced, in polynomial time, to the elementary deduction problems, which amounts to solving certain equations in the underlying individual equational theories. We further show that this result extends to combinations of disjoint AC-convergent theories whereby the decidability of intruder deduction under the combined theory reduces to the decidability of elementary deduction in each constituent theory. Although various researchers have reported similar results for individual cases, our work shows that these results can be obtained using a systematic and uniform methodology based on the sequent calculus.

    Original languageEnglish
    Title of host publicationRewriting Techniques and Applications - 20th International Conference, RTA 2009, Proceedings
    Pages103-117
    Number of pages15
    DOIs
    Publication statusPublished - 2009
    Event20th International Conference on Rewriting Techniques and Applications, RTA 2009 - Brasilia, Brazil
    Duration: 29 Jun 20091 Jul 2009

    Publication series

    NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
    Volume5595 LNCS
    ISSN (Print)0302-9743
    ISSN (Electronic)1611-3349

    Conference

    Conference20th International Conference on Rewriting Techniques and Applications, RTA 2009
    Country/TerritoryBrazil
    CityBrasilia
    Period29/06/091/07/09

    Fingerprint

    Dive into the research topics of 'A proof theoretic analysis of intruder theories'. Together they form a unique fingerprint.

    Cite this