Due to their growing popularity and computational cost, deep neural networks (DNNs) are being targeted for hardware acceleration. A popular architecture for DNN acceleration, adopted by the Google Tensor Processing Unit (TPU), utilizes a systolic array based matrix multiplication unit at its core. This paper deals with the design of faulttolerant, systolic array based DNN accelerators for high defect rate technologies. To this end, we empirically show that the classification accuracy of a baseline TPU drops significantly even at extremely low fault rates (as low as 0:006%). We then propose two novel strategies, faultaware pruning (FAP*) and fault-aware pruning+retraining (FAP*+T), that enable the TPU to operate at fault rates of up to 50%, with negligible drop in classification accuracy (as low as 0:1%) and no run-time performance overhead. The FAP*+T does introduce a one-time retraining penalty per TPU chip before it is deployed, but we propose optimizations that reduce this one-time penalty to under 3 minutes. The penalty is then amortized over the entire lifetime of the TPU’s operation.

High accuracy and ever-increasing computing power have made deep neural networks (DNNs) the algorithm of choice for various machine learning, computer vision, and image processing applications across the computing spectrum. To this end, Google developed the tensor processing unit (TPU) to accelerate the computationally intensive matrix multiplication operation of a DNN on its systolic array architecture. Faults manifested in the datapath of such a systolic array due to latent manufacturing defects or single-event effects may lead to functional safety (FuSa) violation. Although DNNs are known to resist minor perturbations with their inherent fault-tolerant characteristics, we show that the classification accuracy of the model plummets from 97.4% to 7.75% with a minimal fault rate of 0.0003% in the accelerator, implying catastrophic circumstances when deployed across mission-critical systems. Hence, to ensure FuSa of such accelerators, this article provides an extensive FuSa assessment of the accelerator exposed to faults in the datapath, by varying the network parameters, position, and characteristics of the induced error across multiple exhaustive data sets. Furthermore, we propose two novel strategies to obtain a diminutive set of functional test patterns to detect FuSa violation in a DNN accelerator. Our experimental results demonstrate that the obtained test sets can achieve an average of 92.63% (in some cases, up to 100%) fault coverage with cardinality as low as 0.1% of the entire test data set.

Malware can range from simple adware to stealthy kernel control-flow modifying rootkits. Although anti-virus software is popular, an ongoing cat-and-mouse cycle of anti-virus development and malware that thwarts the anti-virus has ensued. More recently, trusted hardware-based malware detection techniques are being developed on the premise that it is easier to bypass software-based defenses than hardware-based counterparts. One such approach is the use of hardware performance counters (HPCs) to detect malware for Linux and Android platforms. This paper, for the first time, presents an analytical framework to investigate the security provided by HPC-based malware detection techniques. The HPC readings are periodically monitored over the duration of the program execution for comparison with a golden HPC reading. We develop a mathematical framework to investigate the probability of malware detection, when HPCs are monitored at a pre-determined sampling interval. In other words, given a program, a set of HPCs, and a sampling rate, the framework can be employed to analyze the probability of malware detection.

This paper presents RTL-ConTest, a Register Transfer Level (RTL) security vulnerability detection algorithm, that extracts critical process flows from a RTL design and executes RTL-level concolic testing to generate security test cases for identifying critical exploits manifested in a System-on-Chip (SoC). The efficiency of the proposed approach is evaluated on open source RISC-V-based SoCs. Our technique is successful in detecting the security vulnerabilities manifested in the processor core as well as in the rest of the SoC, e.g., debug modules, peripherals, etc., thereby providing a thorough vulnerability check on the entire hardware design. As demonstrated by our experimental results, in circumstances where conventional security verification tools are limited, RTL-ConTest furnishes significantly improved efficiency in detecting SoC security vulnerabilities.

The exponential proliferation of Malware over the past decade has threatened system security across a plethora of Internet of Things (IoT) devices. Furthermore, the improvements in computer architectures to include speculative branching and out-of-order executions have engendered new opportunities for adversaries to carry out microarchitectural attacks in these devices. Both Malware and microarchitectural attacks are imperative threats to computing systems, as their behaviors range from stealing sensitive data to total system failure. With the cat-and-mouse game between Anti-Virus Software (AVS) and attackers, the frequent bolstering of AVS induces large computational overhead. Consequently, hardware performance counter (HPC)-based detection strategies augmented with machine learning (ML) classifiers have gained popularity as a low overhead solution in identifying these malicious threats. However, ML models are operated as black boxes, which results in decisions that are not human understandable. Clarity of the models’ results facilitates the development of more robust systems. Existing explainable frameworks are only capable of determining each feature’s impact on a prediction which does not provide meaningful interpretable outcomes for HPC-based intrusion detection. In this article, we address this issue by proposing an explainable HPC-based double regression (HPCDR) ML framework. Our proposed technique provides relevant transparency through isolation of the most malevolent transient window of an application, thereby allowing a user to efficiently locate the pernicious instructions within the program. We evaluated HPCDR on five microarchitectural attacks and two Malware. HPCDR was successfully able to identify the most malicious function manifested in each intrusive application.

Power side-channel (PSC) attacks exploit the dynamic power consumption of cryptographic operations to leak sensitive information about encryption hardware. Therefore, it is necessary to conduct a PSC analysis to assess the susceptibility of cryptographic systems and mitigate potential risks. Existing PSC analysis primarily focuses on postsilicon implementations, which are inflexible in addressing design flaws, leading to costly and time-consuming postfabrication design re-spins. Hence, presilicon PSC analysis is required for the early detection of vulnerabilities to improve design robustness. In this article, we introduce SCAR, a novel presilicon PSC analysis framework based on graph neural networks (GNNs). SCAR converts register-transfer level (RTL) designs of encryption hardware into control-data flow graphs (CDFGs) and use that to detect the design modules susceptible to side-channel leakage. Furthermore, we incorporate a deep-learning-based explainer in SCAR to generate quantifiable and human-accessible explanations of our detection and localization decisions. We have also developed a fortification component as a part of SCAR that uses large-language models (LLMs) to automatically generate and insert additional design code at the localized zone to shore up the side-channel leakage. When evaluated on popular encryption algorithms like advanced encryption standard (AES), RSA, and PRESENT, and postquantum cryptography (PQC) algorithms like Saber and CRYSTALS-Kyber, SCAR, achieves up to 94.49% localization accuracy, 100% precision, and 90.48% recall. Additionally, through explainability analysis, SCAR reduces features for GNN model training by 57% while maintaining comparable accuracy. We believe that SCAR will transform the security-critical hardware design cycle, resulting in faster design closure at a reduced design cost.