An extensive formal analysis of multi-factor authentication protocols
Charlie Jacomme and Steve Kremer. An extensive formal analysis of multi-factor authentication protocols. In Proceedings of the 31st IEEE Computer Security Foundations Symposium (CSF'18), pp. 1–15, IEEE Computer Society Press, Oxford, UK, July 2018.
doi:10.1109/CSF.2018.00008
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Abstract
Passwords are still the most widespread means for authenticating users, even though they have been shown to create huge security problems. This motivated the use of additional authentication mechanisms used in so-called multifactor authentication protocols. In this paper we define a detailed threat model for this kind of protocols: while in classical protocol analysis attackers control the communication network, we take into account that many communications are performed over TLS channels, that computers may be infected by different kinds of malwares, that attackers could perform phishing, and that humans may omit some actions. We formalize this model in the applied pi calculus and perform an extensive analysis and comparison of several widely used protocols - variants of Google 2-step and FIDO's U2F. The analysis is completely automated, generating systematically all combinations of threat scenarios for each of the protocols and using the ProVerif tool for automated protocol analysis. Our analysis highlights weaknesses and strengths of the different protocols, and allows us to suggest several small modifications of the existing protocols which are easy to implement, yet improve their security in several threat scenarios.
BibTeX
@inproceedings{JK-csf18,
abstract = {Passwords are still the most widespread means for
authenticating users, even though they have been
shown to create huge security problems. This
motivated the use of additional authentication
mechanisms used in so-called multifactor
authentication protocols. In this paper we define a
detailed threat model for this kind of protocols:
while in classical protocol analysis attackers
control the communication network, we take into
account that many communications are performed over
TLS channels, that computers may be infected by
different kinds of malwares, that attackers could
perform phishing, and that humans may omit some
actions. We formalize this model in the applied pi
calculus and perform an extensive analysis and
comparison of several widely used protocols -
variants of Google 2-step and FIDO's U2F. The
analysis is completely automated, generating
systematically all combinations of threat scenarios
for each of the protocols and using the ProVerif
tool for automated protocol analysis. Our analysis
highlights weaknesses and strengths of the different
protocols, and allows us to suggest several small
modifications of the existing protocols which are
easy to implement, yet improve their security in
several threat scenarios.},
address = {Oxford, UK},
author = {Jacomme, Charlie and Kremer, Steve},
booktitle = {{P}roceedings of the 31st IEEE Computer Security
Foundations Symposium (CSF'18)},
month = jul,
pages = {1--15},
publisher = {{IEEE} Computer Society Press},
title = {An extensive formal analysis of multi-factor
authentication protocols},
year = 2018,
acronym = {{CSF}'18},
nmonth = 7,
url =
{https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=8429292},
{https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=8429292},
doi = {10.1109/CSF.2018.00008}
}