The Importance of Proofs of Security for Key Establishment Protocols: Formal Analysis of Jan-Chen, Yang-Shen-Shieh, Kim-Huh-Hwang-Lee, Lin-Sun-Hwang, and Yeh-Sun Protocols

摘要

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 revisit recent work of Choo, Boyd, Hitchcock, & Maitland (2004) where they utilize the Bellare, Pointcheval, & Rogaway (2000) computational complexity proof model in a machine specification and analysis (using an automated model checker -- SHVT) for provably-secure key establishment protocol analysis. We then examine several key establishment protocols without proofs of security, namely: protocols due to Jan & Chen (2004), Yang, Shen, & Shieh (1999), Kim, Huh, Hwang, & Lee (2004), Lin, Sun, & Hwang (2000), and Yeh & Sun (2002). Using these protcols as case studies, we demonstrate previously unpublished flaws in these protocols.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.