A Novel Two-Level Protection Scheme against Hardware Trojans on a Reconfigurable CNN Accelerator

With the boom in artificial intelligence (AI), numerous reconfigurable convolution neural network (CNN) accelerators have emerged within both industry and academia, aiming to enhance AI computing capabilities. However, this rapid landscape has also witnessed a rise in hardware Trojan attacks targeted at CNN accelerators, thereby posing substantial threats to the reliability and security of these reconfigurable systems. Despite this escalating concern, there exists a scarcity of security protection schemes explicitly tailored to counteract hardware Trojans embedded in reconfigurable CNN accelerators, and those that do exist exhibit notable deficiencies. Addressing these gaps, this paper introduces a dedicated security scheme designed to mitigate the vulnerabilities associated with hardware Trojans implanted in reconfigurable CNN accelerators. The proposed security protection scheme operates at two distinct levels: the first level is geared towards preventing the triggering of the hardware Trojan, while the second level focuses on detecting the presence of a hardware Trojan post-triggering and subsequently neutralizing its potential harm. Through experimental evaluation, our results demonstrate that this two-level protection scheme is capable of mitigating at least 99.88% of the harm cause by three different types of hardware Trojan (i.e., Trojan within RI, MAC and ReLU) within reconfigurable CNN accelerators. Furthermore, this scheme can prevent hardware Trojans from triggering whose trigger signal is derived from a processing element (PE). Notably, the proposed scheme is implemented and validated on a Xilinx Zynq XC7Z100 platform.