An Obfuscated Hardwired Sequence Control System Generated by High Level Synthesis
Yoshiki Ishigaki, Naoki Fujieda, Yuumi Matsuoka, Kazuki Uyama, Shûichi Ichikawa · 2017
The intellectual property and the security of sequence control systems can be protected by implementing control software as logic circuit. This study examines the use of a commercial High Level Synthesis (HLS) tool to generate the hardwired sequence control obfuscated by opaque predicates. HLS is applied to C codes converted from PLC instructions. For comparison, a traditional method that directly generates HDL is also implemented. The increase of the logic elements with obfuscation using the HLS was almost proportional to the number of bogus instructions. The estimated operating frequency ranged from 89% to 102% of the original system.