Strongly leakage-resilient authenticated key exchange

• Main Authors: CHEN, Rongmao, MU, Yi, YANG, Guomin, SUSILO, Willy, GUO, Fuchun
• Format: text
• Language: English
• Published: Institutional Knowledge at Singapore Management University 2016
• Subjects: Authenticated key exchange; Challenge-dependent leakage; Smooth projective hash function; Strong randomness extractor; Information Security
• Online Access: https://ink.library.smu.edu.sg/sis_research/7424; https://ink.library.smu.edu.sg/context/sis_research/article/8427/viewcontent/Strongly_leakage_resilient_authenticated_key_exchange.pdf
• Institution: Singapore Management University

Authenticated Key Exchange (AKE) protocols have been widely deployed in many real-world applications for securing communication channels. In this paper, we make the following contributions. First, we revisit the security modelling of leakage-resilient AKE protocols, and show that the existing models either impose some unnatural restrictions or do not sufficiently capture leakage attacks in reality. We then introduce a new strong yet meaningful security model, named challenge-dependent leakage-resilient eCK (CLR- eCKCLR- eCK) model, to capture challenge-dependent leakage attacks on both long-term secret key and ephemeral secret key (i.e., randomness). Second, we propose a general framework for constructing one-round CLR- eCKCLR- eCK-secure AKE protocols based on smooth projective hash functions (SPHFs). Finally, we present a practical instantiation of the general framework based on the Decisional Diffie-Hellman assumption without random oracle. Our result shows that the instantiation is efficient in terms of the communication and computation overhead and captures more general leakage attacks.