FPGA-based high throughput XTS-AES encryption/decryption for storage area network

The key issue to improve the performance for secure large-scale Storage Area Network (SAN) applications lies in the speed of its encryption/decryption module. Software-based encryption/decryption cannot meet throughput requirements. To solve this problem, we propose a FPGA-based XTS-AES encryption/decryption to suit the needs for secure SAN applications with high throughput requirements. Besides throughput, area optimization is also considered in this proposed design. First, we reuse the same AES encryption to produce the tweak value and unify the operations of AES encryption/decryption in XTS-AES encryption/decryption. Second, we transfer the computations of AES encryption/decryption from GF(2⁸) to GF(2⁴)², which enables us move the map and the inverse map functions outside the AES round. Third, we propose to support the SubBytes and the inverse SubBytes by the same hardware component. Finally, pipelined registers have been inserted into the proposed unrolled architecture for XTS-AES encryption/decryption. The experiments show that the proposed design achieves 36.2 Gbits/s throughput using 6784 slices on XC6VLX240T FPGA.