Information leakage in encrypted key exchange

Shai Halevi, Huijia Lin

Zongyang Zhang, Sherman S. M. Chow, Zhenfu Cao

Suvradip Chakraborty, Janaka Alawatugoda, Rangan Chandrasekaran Pandu

We present a new approach to construct several leakage-resilient cryptographic primitives, including leakage-resilient public-key encryption (PKE) schemes, authenticated key exchange (AKE) protocols and low-latency key exchange (LLKE) protocols. To this end, we introduce a new primitive called leakage-resilient non-interactive key exchange (LR-NIKE) protocol. We introduce an appropriate security model for LR-NIKE protocols in the bounded memory leakage (BML) settings. We then show a secure construction of the LR-NIKE protocol in the BML setting that achieves an optimal leakage rate, i.e., 1 – o(1). Our construction of LR-NIKE requires a minimal use of a leak-free hardware component. We argue that the use of such a leak-free hardware component seems to be unavoidable in any construction of an LR-NIKE protocol, even in the BML setting. Finally, we show how to construct the aforementioned leakage-resilient primitives from such an LR-NIKE protocol as summarized below. All these primitives also achieve the same (optimal) leakage rate as the underlying LR-NIKE protocol. We show how to construct a leakage-resilient (LR) IND-CCA-2-secure PKE scheme in the BML model generically from a bounded LR-NIKE (BLR-NIKE) protocol. Our construction of LR-IND-CCA-2 secure PKE differs significantly from the state-of-the-art constructions of these primitives, which mainly use hash proof techniques to achieve leakage resilience. Moreover, our transformation preserves the leakage-rate of the underlying BLR-NIKE protocol. We introduce a new leakage model for AKE protocols, in the BML setting, and present a leakage-resilient AKE protocol construction from the LR-NIKE protocol. We introduce the first-ever leakage model for LLKE protocols in the BML setting and the first construction of such a leakage-resilient LLKE from the LR-NIKE protocol.

圭介 田中, Keisuke Tanaka, 均 並木 +3 more

Suvradip Chakraborty, Janaka Alawatugoda, Chandrasekaran Pandu Rangan

Abstract We present a new approach to construct several leakage-resilient cryptographic primitives, including leakage-resilient public-key encryption (PKE) schemes, authenticated key exchange (AKE) protocols and low-latency key exchange (LLKE) protocols. To this end, we introduce a new primitive called leakage-resilient non-interactive key exchange (LR-NIKE) protocol. We introduce an appropriate security model for LR-NIKE protocols in the bounded memory leakage (BML) settings. We then show a secure construction of the LR-NIKE protocol in the BML setting that achieves an optimal leakage rate, i.e., 1 – o (1). Our construction of LR-NIKE requires a minimal use of a leak-free hardware component. We argue that the use of such a leak-free hardware component seems to be unavoidable in any construction of an LR-NIKE protocol, even in the BML setting. Finally, we show how to construct the aforementioned leakage-resilient primitives from such an LR-NIKE protocol as summarized below. All these primitives also achieve the same (optimal) leakage rate as the underlying LR-NIKE protocol. We show how to construct a leakage-resilient (LR) IND-CCA-2-secure PKE scheme in the BML model generically from a bounded LR-NIKE (BLR-NIKE) protocol. Our construction of LR-IND-CCA-2 secure PKE differs significantly from the state-of-the-art constructions of these primitives, which mainly use hash proof techniques to achieve leakage resilience. Moreover, our transformation preserves the leakage-rate of the underlying BLR-NIKE protocol. We introduce a new leakage model for AKE protocols, in the BML setting, and present a leakage-resilient AKE protocol construction from the LR-NIKE protocol. We introduce the first-ever leakage model for LLKE protocols in the BML setting and the first construction of such a leakage-resilient LLKE from the LR-NIKE protocol.

Michèle Feltz