Paper 2013/871

A Unified Security Model of Authenticated Key Exchange with Specific Adversarial Capabilities

Weiqiang Wen and Libin Wang and Jiaxin Pan

Abstract

The most widely accepted models in the security proofs of Authenticated Key Exchange protocols are the Canetti-Krawczyk model and the extended Canetti-Krawczyk model that admit different adversarial queries with ambiguities and incomparable strength. It is desirable to incorporate specific and powerful adversarial queries into a single unified security model and establish a stronger security notion. Concerning the security of one-round implicitly authenticated Diffie-Hellman key exchange protocols, we present a unified security model that has many advantages over the previous ones. In the model, a system environment is set up, all of the adversarial queries are practically interpreted and definitely characterized through the physical environment, and some rigorous rules of secret leakage are also specified. To demonstrate the usability of our model, a new protocol based on the OAKE protocol is proposed, which satisfies the presented stronger security notion and at the same time attains high efficiency as the OAKE protocol. The protocol is proven secure in random oracle model under the gap Diffie-Hellman assumption.