An Efficient and Secure Cipher Scheme for Filter Bank Multi-Carrier Systems

Reem Melki, Hassan Noura, Ali Chehab


Future mobile systems support heterogeneous devices with diverse requirements and hence require flexible and efficient allocation of available time-frequency resources. A promising multi-carrier modulation scheme considered for 5G systems is the filter bank multi-carrier (FBMC) scheme. FBMC offers better spectral characteristics compared to conventional orthogonal frequency division multiplexing (OFDM) by combining individual or groups of sub-carriers and applying a shaping filter to achieve better spectral containment. While current research on FBMC has mainly focused on reducing the signal processing complexity associated with FBMC as well as coping with the issue of the increased symbol period, analysis of the security aspects of FBMC systems remains largely unattempted. In this paper, we take the first step in this direction and propose a new cipher scheme to guard against adversaries, while preserving the promised performance of FBMC. The proposed cipher scheme is based on dynamic permutation of time-domain symbols, and a dynamic key approach that generates session keys by exploiting the randomness of the underlying physical communication channel. The randomness of the channel-dependent dynamic key ensures robustness of the cipher solution. The cipher scheme is shown to be highly efficient since it requires only one iteration with one simple operation. Experimental simulations demonstrate that the proposed scheme strikes a good balance between performance and security.


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