Low-cost robust anti-removal logic for protecting functionally obfuscated DSP core against removal attack

Abstract

Digital signal processing (DSP) cores (kernels) are key components of modern consumer electronics devices. However, protection of DSP kernels is very crucial considering its vulnerability to hardware threats such as reverse engineering (RE). Functional obfuscation is one of the security mechanisms which provide protection against RE. However, functional obfuscation logic is in itself vulnerable to removal attack. This Letter presents a novel anti-removal logic (ARL) unit which ensures protection against the removal attack on functional obfuscation logic. Further, the ARL unit is itself safeguarded against removal attack by incorporating design architecture customisation and camouflaging. Designer can customise and camouflage the internal gate structure network of the ARL blocks post-synthesis (post-mapping and fitting). The proposed ARL unit integrated with functionally obfuscated DSP design, yielded lightweight and highly secured solution against removal attack when compared to an existing approach. The proposed approach reported on an average 42.57% reduction in gate count and on an average 66.67% enhancement in security compared to a recent existing approach. © The Institution of Engineering and Technology 2019.