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The globalized semiconductor supply chain significantly increases the risk of exposing System-on-Chip (SoC) designs to malicious implants, popularly known as hardware Trojans. Traditional simulation-based validation is unsuitable for detection of carefully-crafted hardware Trojans with extremely rare trigger conditions. While machine learning (ML) based Trojan detection approaches are promising due to their scalability as well as detection accuracy, ML-based methods themselves are vulnerable from Trojan attacks. In this paper, we propose a robust backdoor attack on ML-based Trojan detection algorithms to demonstrate this serious vulnerability. The proposed framework is able to design an AI Trojan and implant it inside the ML model that can be triggered by specific inputs. Experimental results demonstrate that the proposed AI Trojans can bypass state-of-the-art defense algorithms. Moreover, our approach provides a fast and cost-effective solution in achieving 100% attack success rate that significantly outperforms state-of-the art approaches based on adversarial attacks. 

Machine learning (ML) is successful in achieving human-level performance in various fields. However, it lacks the ability to explain an outcome due to its black-box nature. While recent efforts on explainable ML has received significant attention, the existing solutions are not applicable in real-time systems since they map interpretability as an optimization problem, which leads to numerous iterations of time-consuming complex computations. To make matters worse, existing implementations are not amenable for hardware-based acceleration. In this paper, we propose an efficient framework to enable acceleration of explainable ML procedure with hardware accelerators. We explore the effectiveness of both Tensor Processing Unit (TPU) and Graphics Processing Unit (GPU) based architectures in accelerating explainable ML. Specifically, this paper makes three important contributions. (1) To the best of our knowledge, our proposed work is the first attempt in enabling hardware acceleration of explainable ML. (2) Our proposed solution exploits the synergy between matrix convolution and Fourier transform, and therefore, it takes full advantage of TPU's inherent ability in accelerating matrix computations. (3) Our proposed approach can lead to real-time outcome interpretation. Extensive experimental evaluation demonstrates that proposed approach deployed on TPU can provide drastic improvement in interpretation time (39x on average) as well as energy efficiency (69x on average) compared to existing acceleration techniques. 

Spectre and Meltdown attacks exploit security vulnerabilities of advanced architectural features to access inherently concealed memory data without authorization. Existing defense mechanisms have three major drawbacks: (i) they can be fooled by obfuscation techniques, (ii) the lack of transparency severely limits their applicability, and (iii) it can introduce unacceptable performance degradation. In this paper, we propose a novel detection scheme based on explainable machine learning to address these fundamental challenges. Specifically, this paper makes three important contributions. (1) Our work is the first attempt in applying explainable machine learning for Spectre and Meltdown attack detection. (2) Our proposed method utilizes the temporal differences of hardware events in sequential timestamps instead of overall statistics, which contributes to the robustness of ML models against evasive attacks. (3) Extensive experimental evaluation demonstrates that our approach can significantly improve detection efficiency (38.4% on average) compared to state-of-the-art techniques. 

Deep neural networks (DNNs) play an important role in machine learning due to its outstanding performance compared to other alternatives. However, DNNs are usually not suitable for safety-critical applications since DNNs can be easily fooled by well-crafted adversarial examples. To address this issue, spectral normalization (SN) technique was proposed to counter adversarial attacks, which ensures that the trained model has low sensitivity towards the disturbance of input samples. Unfortunately, this strategy requires exact computation of spectral norm, which is computation intensive and impractical for large-scale networks. In this paper, we introduce an acceleration technique for spectral normalization based on Fourier transform and layer separation. The proposed method provides DNNs with promising security protection while maintaining minimized time cost, which turns SN from a theoretically feasible approach to a practically useful framework. Experimental evaluation using autonomous systems demonstrates that our acceleration method is able to significantly improve both time efficiency (up to 60%) and model robustness (61% on average) compared with the state-of-the-art spectral normalization in real-world applications. 

Due to globalized semiconductor supply chain, there is an increasing risk of exposing System-on-Chip (SoC) designs to malicious implants, popularly known as hardware Trojans. Unfortunately, traditional simulation-based validation using millions of test vectors is unsuitable for detecting stealthy Trojans with extremely rare trigger conditions due to exponential input space complexity of modern SoCs. There is a critical need to develop efficient Trojan detection techniques to ensure trustworthy SoCs. While there are promising test generation approaches, they have serious limitations in terms of scalability and detection accuracy. In this paper, we propose a novel logic testing approach for Trojan detection using an effective combination of testability analysis and reinforcement learning. Specifically, this paper makes three important contributions. 1) Unlike existing approaches, we utilize both controllability and observability analysis along with rareness of signals to significantly improve the trigger coverage. 2) Utilization of reinforcement learning considerably reduces the test generation time without sacrificing the test quality. 3) Experimental results demonstrate that our approach can drastically improve both trigger coverage (14.5% on average) and test generation time (6.5 times on average) compared to state-of-the-art techniques. 

Malicious software, popularly known as malware, is a serious threat to modern computing systems. A comprehensive cybercrime study by Ponemon Institute highlights that malware is the most expensive attack for organizations, with an average revenue loss of $2.6 million per organization in 2018 (11% increase compared to 2017). Recent high-profile malware attacks coupled with serious economic implications have dramatically changed our perception of threat from malware. Software-based solutions, such as anti-virus programs, are not effective since they rely on matching patterns (signatures) that can be easily fooled by carefully crafted malware with obfuscation or other deviation capabilities. Moreover, software-based solutions are not fast enough for real-time malware detection in safety-critical systems. In this paper, we investigate promising approaches for hardware-assisted malware detection using machine learning. Specifically, we explore how machine learning can be effective for malware detection utilizing hardware performance counters, embedded trace buffer as well as on-chip network traffic analysis. 

Reliability and trustworthiness are dominant factors in designing System-on-Chips (SoCs) for a variety of applications. Malicious implants, such as hardware Trojans, can lead to undesired information leakage or system malfunction. To ensure trustworthy computing, it is critical to develop efficient Trojan detection techniques. While existing delay-based side-channel analysis is promising, it is not effective due to two fundamental limitations: (i) The difference in path delay between the golden design and Trojan inserted design is negligible compared with environmental noise and process variations. (ii) Existing approaches rely on manually crafted rules for test generation, and require a large number of simulations, making it impractical for industrial designs. In this paper, we propose a novel test generation method using reinforcement learning for delay-based Trojan detection. This paper makes three important contributions. 1) Unlike existing methods that rely on the delay difference of a few gates, our proposed approach utilizes critical path analysis to generate test vectors that can maximize the side-channel sensitivity. 2) To the best of our knowledge, our approach is the first attempt in applying reinforcement learning for efficient test generation to detect Trojans using delay-based analysis. 3) Our experimental results demonstrate that our method can significantly improve both side-channel sensitivity (59% on average) and test generation time (17x on average) compared to state-of-the-art test generation techniques.