Kleptography in Authentication Protocols: Why is it Still Possible?

Abstract

Network authentication frequently relies on nonces, and even widely deployed protocols still rely on random nonces, although they might enable kleptography attacks. Notably, for TLS a kleptography-based covert channel has been published, and despite a proposal to cure this weakness via controlled randomness including backward compatibility, the protocol description is not updated. We investigate if lack of bandwidth, i.e., lack of applicability, could be a reason not to care for such an update. Moreover, we give examples of other authentication protocols that might suffer from a similar weakness, and that possibly might profit from a similar cure, thus indicating necessity of further research.

Publication
Proceedings of the European Interdisciplinary Cybersecurity Conference (EICC)

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