Efficient and Secure Physical Encryption Scheme for Low-Power Wireless M2M Devices
Hassan Noura, Reem Melki, Ali Chehab, Mohammad M. Mansour, Steven Martin · 2018
Recently, physical layer security has emerged as a promising security scheme for wireless networks, in contrast to traditional solutions that mainly rely on upper network layers. As such, several physical layer encryption algorithms that benefit from the random characteristics of physical channels have appeared in the literature. However, the majority of these schemes lack the notion of secrecy and dynamicity. In this paper, we focus on enhancing the physical layer encryption for wireless machine-to-machine devices, which share the same channel, with the aim of striking a good balance between performance and security robustness. The main idea is to perform encryption at the physical layer after symbol modulation. The cipher scheme is based on one round and one operation that reduces the encryption overhead in terms of latency and required resources. Furthermore, we propose a dynamic key approach that combines a pre-shared/stored secret key with a dynamic nonce extracted from the channel information to generate a dynamic key. The main advantage of the dynamic key approach is that it achieves a high-security level with minimal overhead. The dynamic key can be changed frequently upon any change in channel parameters or upon starting a new session. In addition to data encryption, a preamble encryption scheme is also proposed to prevent unauthorized synchronization or channel estimation by illegitimate users. Finally, security and performance analyses are performed to demonstrate the validity, efficiency and robustness of the proposed approach.