High-performance and energy-efficient sliced AES multi-block encryption for LTE mobile devices

In this paper we present an efficient software implementation of the Advanced Encryption Standard (AES) used in the confidentiality algorithm of the Long Term Evolution (LTE) protocol. Our implementation is based on slicing and merging the bytes of several data blocks to exploit processor´s architecture width for multi-block encryption. In addition, an appropriate lookup table and data organization in memory are applied, combined with media processing instructions in order to enhance the performance of AES in embedded environments. Other optimized software implementations from literature are also explored and evaluated in comparison to the proposed implementation with respect to processing throughput and energy consumption using a multi-core based mobile phone platform. Simulation results show that the proposed implementation is the fastest among other implementations and achieves improvements in performance up to 69% while providing 59% of energy savings. Moreover, the presented implementation is scalable for multi-core execution. When running on two cores, it fulfills the LTE data rate of 100 Mbit/s and extends energy savings to 68%, leading to a total of 13 times improvement in energy efficiency.