Performance Evaluation of SHA-2 Standard vs. SHA-3 Finalists on Two Freescale Platforms

Embedded devices are ubiquitously involved in a large variety of security applications which heavily rely on the computation of hash functions. Roughly, two alternatives for speeding up computations co-exist in these resource constrained devices: parallel processing and hardware acceleration. Needles to say, multi-core devices are clearly the next step in embedded systems due to clear technological limitations on single processor frequency. Hardware accelerators are long known to be a cheaper approach for costly cryptographic functions. The authors analysis is focused on the five SHA-3 finalists which are also contrasted to the previous SHA-2 standard and to the widespread MD5. On the hardware side, the authors deploy their implementations on two platforms from Freescale: a S12X core equipped with an XGATE coprocessor and a Kinetis K60 core equipped with a crypto co-processor. These platforms differ significantly in terms of computational power, the first is based on a 16-bit Freescale proprietary architecture while the former relies on a more recent 32-bit Cortex core. The authors' experimental results show mixed performances between the old standard and the new candidates. Some of the new candidates clearly outperform the old standard in terms of both computational speed and memory requirements while others do not. Bottom line, on the 16 bit platform BLAKE and Grostl are the top performers while on the 32-bit platform Keccak, Blake and Skein give the best results.