On communication models when verifying equivalence properties
Kushal Babel, Vincent Cheval, and Steve Kremer. On communication models when verifying equivalence properties. In Proceedings of the 6th International Conference on Principles of Security and Trust (POST'17), pp. 141–163, Lecture Notes in Computer Science 10204, Springer, Uppsala, Sweden, April 2017. Best paper nominee.
doi:10.1007/978-3-662-54455-6
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Abstract
Symbolic models for security protocol verification, following the sem-inal ideas of Dolev and Yao, come in many flavors, even though they share the same ideas. A common assumption is that the attacker has complete control over the network: he can therefore intercept any message. Depending on the precise model this may be reflected either by the fact that any protocol output is directly routed to the adversary, or communications may be among any two participants, including the attacker --- the scheduling between which exact parties the communication happens is left to the attacker. These two models may seem equivalent at first glance and, depending on the verification tools, either one or the other semantics is implemented. We show that, unsurprisingly, they indeed coincide for reachability properties. However, when we consider indistinguishability properties, we prove that these two semantics are incomparable. We also introduce a new semantics, where internal communications are allowed but messages are always eavesdropped by the attacker. We show that this new semantics yields strictly stronger equivalence relations. We also identify two subclasses of protocols for which the three semantics coincide. Finally, we implemented verification of trace equivalence for each of these semantics in the APTE tool and compare their performances on several classical examples.
BibTeX
@inproceedings{BCK-post17,
abstract = {Symbolic models for security protocol verification,
following the sem-inal ideas of Dolev and Yao, come
in many flavors, even though they share the same
ideas. A common assumption is that the attacker has
complete control over the network: he can therefore
intercept any message. Depending on the precise
model this may be reflected either by the fact that
any protocol output is directly routed to the
adversary, or communications may be among any two
participants, including the attacker --- the
scheduling between which exact parties the
communication happens is left to the attacker. These
two models may seem equivalent at first glance and,
depending on the verification tools, either one or
the other semantics is implemented. We show that,
unsurprisingly, they indeed coincide for
reachability properties. However, when we consider
indistinguishability properties, we prove that these
two semantics are incomparable. We also introduce a
new semantics, where internal communications are
allowed but messages are always eavesdropped by the
attacker. We show that this new semantics yields
strictly stronger equivalence relations. We also
identify two subclasses of protocols for which the
three semantics coincide. Finally, we implemented
verification of trace equivalence for each of these
semantics in the APTE tool and compare their
performances on several classical examples. },
address = {Uppsala, Sweden},
author = {Babel, Kushal and Cheval, Vincent and Kremer, Steve},
booktitle = {{P}roceedings of the 6th International Conference on
Principles of Security and Trust (POST'17)},
month = apr,
series = {Lecture Notes in Computer Science},
volume = 10204,
publisher = {Springer},
doi = {10.1007/978-3-662-54455-6},
pages = {141--163},
title = {On communication models when verifying equivalence
properties},
year = 2017,
acronym = {{POST}'17},
nmonth = 4,
url = {https://hal.inria.fr/hal-01450898/},
note = {\textbf{\href{https://www.etaps.org/index.php/2017/best-papers}{Best paper nominee}}},
}