A Pipelined AES and SM4 Hardware Implementation for Multi-tasking Virtualized Environments

Virtualization techniques are becoming increasingly prevalent and are driving trends in hardware development to offer parallelization support for multi-tasking. Existing works on hardware designs of the Advanced Encryption Standard (AES) and SM4 encryption algorithms have primarily focused on optimizing metrics such as throughput and area, but have not fully addressed the demands in virtualized environments. In this article, we propose innovative optimization schemes that partition the resources in AES and SM4 cipher modules into smaller, independent units that can execute tasks from different guests in parallel. Such designs can improve hardware utilization efficiency and enhance the user experience in virtualized environments. Our FPGA-validated designs achieve comparable circuit performance in terms of throughput/area efficiency to existing work. Experiments show that in virtualized environments lacking block-wise parallelism (e.g., cipher block chaining (CBC) mode), our approach reduces context switches over 50% and decreases average task pending time around 75% with similar hardware needs.