Visible to the public Verifying Accountability for Unbounded Sets of Participants

TitleVerifying Accountability for Unbounded Sets of Participants
Publication TypeConference Paper
Year of Publication2021
AuthorsMorio, Kevin, Künnemann, Robert
Conference Name2021 IEEE 34th Computer Security Foundations Symposium (CSF)
Keywordsaccountability, composability, computer security, Electronic voting, formal-methods, Protocols, pubcrawl, Security-Protocols, trustworthiness, verification
AbstractLittle can be achieved in the design of security protocols without trusting at least some participants. This trust should be justified or, at the very least, subject to examination. One way to strengthen trustworthiness is to hold parties accountable for their actions, as this provides a strong incentive to refrain from malicious behavior. This has led to an increased interest in accountability in the design of security protocols. In this work, we combine the accountability definition of Kunnemann, Esiyok, and Backes [21] with the notion of case tests to extend its applicability to protocols with unbounded sets of participants. We propose a general construction of verdict functions and a set of verification conditions that achieve soundness and completeness. Expressing the verification conditions in terms of trace properties allows us to extend TAMARIN - a protocol verification tool - with the ability to analyze and verify accountability properties in a highly automated way. In contrast to prior work, our approach is significantly more flexible and applicable to a wider range of protocols.
DOI10.1109/CSF51468.2021.00032
Citation Keymorio_verifying_2021