An Efficient Leakage-Resilient Authenticated Key Exchange Protocol Suitable for IoT Devices

Authenticated key exchange (AKE) protocol for client–server environments is a significant cryptographic primitive that provides communication confidentiality and mutual authentication between clients and servers. In an Internet of Things (IoT) environment, clients typically employ IoT devices with limited computing capability to interact with servers through the Internet. Numerous AKE protocols suitable for IoT devices, called AKE-IoT protocols, have been proposed. Recently, side-channel attacks have been conducted to defeat traditional cryptographic protocols because a side-channel adversary can retrieve partial content of long-term or short-term secret keys. Several leakage-resilient AKE (LRAKE) protocols were presented to counteract such attacks. Unfortunately, the existing LRAKE protocols are not suitable for IoT devices because expensive pairing operations are required for client sides. In this article, we propose the first efficient LRAKE protocol suitable for IoT devices, named LRAKE-IoT. By the unbalanced computation method, no pairing operation is required for client sides in our protocol. In the generic bilinear pairing group model, security analysis is conducted to demonstrate the security of the proposed protocol in the continuous-leakage-resilient extended-Canetti–Krawczyk model. Finally, computational experiences on two IoT devices are given to show that the proposed protocol is well-suited for IoT devices.