Refuting the Security Claims of Mathuria and Jain (2005) Key Agreement Protocols

Despite the importance of proofs in assuring protocol implementers about the security properties of key establishment protocols, many protocol designers fail to provide any proof of security. Flaws detected long after the publication and/or implementation of protocols will erode the credibility of key establishment protocols. We examine the class of key agreement protocols (without proofs of security) due to Mathuria and Jain (2005). Using these protocols as case studies, we demonstrate previously unpublished flaws in these protocols. We may speculate that such errors could have been found by protocol designers if proofs of security were to be constructed, and hope this work will encourage future protocol designers to provide proofs of security.