Biblio

Hardware Trojans are modifications made by malicious insiders or third party providers during the design or fabrication phase of the IC (Integrated Circuits) design cycle in a covert manner. These cause catastrophic consequences ranging from manipulating the functionality of individual blocks to disabling the entire chip. Thus, a need for detecting trojans becomes necessary. In this work, we propose a deep learning based approach for detecting trojans in IC chips. In particular, we insert trojans at the circuit-level and generate data by measuring power during normal operation and under attack. Further, we develop deep learning models using Neural networks and Auto-encoders to analyze datasets for outlier detection by profiling the normal behavior and leveraging them to detect anomalies in power consumption. Our approach is generic and non-invasive in that it can be applied to any block without any modifications to the design. Evaluation of the proposed approach shows an accuracy ranging from 92.23% to 99.33% in detecting trojans.

The utilization of Third-party modules is very common nowadays. Hence, combating Hardware Trojans affecting the applications' functionality and data security becomes inevitably essential. This paper focuses on the detection/masking of Hardware Trojans' undesirable effects concerned with spying and information leakage due to the growing care about applications' data confidentiality. It is assumed here that the Trojan-infected system consists mainly of a Microprocessor module (MP) followed by an encryption module and then a Medium Access Control (MAC) module. Also, the system can be application-specific integrated circuit (ASIC) based or Field Programmable Gate Arrays (FPGA) based. A general solution, including encryption, CRC encoder/decoder, and zero padding modules, is presented to handle such Trojans. Special cases are then discussed carefully to prove that Trojans will be detected/masked with a corresponding overhead that depends on the Trojan's location, and the system's need for encryption. An implementation of the CRC encoder along with the zero padding module is carried out on an Altera Cyclone IV E FPGA to illustrate the extra resource utilization required by such a system, given that it is already using encryption.

For the purpose of stealthiness, trigger-based Hardware Trojans(HTs) tend to have at least one trigger signal with an extremely low transition probability to evade the functional verification. In this paper, we discuss the correlation between poor testability and low transition probability, and then propose a kind of systematic Trojan trigger model with extremely low transition probability but reasonable testability, which can disable the Controllability and Observability for hardware Trojan Detection (COTD) technique, an efficient HT detection method based on circuits testability. Based on experiments and tests on circuits, we propose that the more imbalanced 0/1-controllability can indicate the lower transition probability. And a trigger signal identification method using the imbalanced 0/1-controllability is proposed. Experiments on ISCAS benchmarks show that the proposed method can obtain a 100% true positive rate and average 5.67% false positive rate for the trigger signal.

Always-On Denial of Service (DoS) Trojans with power drain payload can be disastrous in systems where on-chip power resources are limited. These Trojans are designed so that they have no impact on system behavior and hence, harder to detect. A formal verification method is presented to detect sequential always-on DoS Trojans in pipelined circuits and pipelined microprocessors. Since the method is proof-based, it provides a 100% accurate classification of sequential Trojan components. Another benefit of the approach is that it does not require a reference model, which is one of the requirements of many Trojan detection techniques (often a bottleneck to practical application). The efficiency and scalability of the proposed method have been evaluated on 36 benchmark circuits. The most complex of these benchmarks has as many as 135,898 gates. Detection times are very efficient with a 100% rate of detection, i.e., all Trojan sequential elements were detected and all non-trojan sequential elements were classified as such.

Nowadays malicious vendors can easily insert hardware Trojans into integrated circuit chips as the entire integrated chip supply chain involves numerous design houses and manufacturers on a global scale. It is thereby becoming a necessity to expose any possible hardware Trojans, if they ever exist in a chip. A typical Trojan circuit is made of a trigger and a payload that are interconnected with a trigger net. As trigger net can be viewed as the signature of a hardware Trojan, in this paper, we propose a gate-level hardware Trojan detection method and model that can be applied to screen the entire chip for trigger nets. In specific, we extract the trigger-net features for each net from known netlists and use the machine learning method to train multiple detection models according to the trigger modes. The detection models are used to identify suspicious trigger nets from the netlist of the integrated circuit under detection, and score each net in terms of suspiciousness value. By flagging the top 2% suspicious nets with the highest suspiciousness values, we shall be able to detect majority hardware Trojans, with an average accuracy rate of 96%.

There is an increasing concern about possible hostile modification done to ICs, which are used in various critical applications. Such malicious modifications are referred to as Hardware Trojan. A novel procedure to detect these malicious Trojans using Genetic algorithm along with the logical masking technique which masks the Trojan module when embedded is presented in this paper. The circuit features such as transition probability and SCOAP are used as suitable parameters to identify the rare nodes which are more susceptible for Trojan insertion. A set of test patterns called optimal test patterns are generated using Genetic algorithm to claim that these test vectors are more feasible to detect the presence of Trojan in the circuit under test. The proposed methodologies are validated in accordance with ISCAS '85 and ISCAS '89 benchmark circuits. The experimental results proven that it achieves maximum Trigger coverage, Trojan coverage and is also able to successfully mask the inserted Trojan when it is triggered by the optimal test patterns.

Hardware Trojans are malicious modules causing vulnerabilities in designs. Secured hardware designs are desirable in almost all applications. So, it is important to make a trustworthy design that actually exposes malfunctions when a Trojan is present in it. Recently, ring oscillator based detection methods are gaining prominence as they help in detecting Trojans accurately. In this work, a non-destructive method of Trojan detection by modifying the circuit paths into oscillators is proposed. The change in frequencies of ring oscillators upon taking the process corners into account, indicate the presence of Trojans. Since Transient Effect Ring Oscillators (TERO) are also emerging as a good alternative to classical ring oscillators in Trojan detection, an effort is made to analyze the detection capability. Evaluation is done using ISCAS'85 benchmark circuits. Comparison is done in terms of frequency and findings indicate that TERO based Trojan detection is precise. Evaluation is carried out using Xilinx Vivado and ModelSim platforms.

Memristive nano crossbar array has paved the way for high density memories but in a very low power environment. But such high density circuits face multiple problems at the time of implementation. The sneak path problem in crossbar array is one such problem which causes difficulty in distinguishing the logical states of the memristors. On the other hand, hardware Trojan causes malfunctioning of the circuit or performance degradation. If any of these are present in the nano crossbar, it is difficult to identify whether the performance degradation is due to the sneak path problem or due to that of Hardware Trojan.This paper makes a comparative study of the sneak path problem and the hardware Trojan to understand the performance difference between both. It is observed that some parameters are affected by sneak path problem but remains unaffected in presence of Hardware Trojan and vice versa. Analyzing these parameters, we can classify whether the performance degradation is due to sneak path or due to Hardware Trojan. The experimental results well establish the proposed methods of detection of hardware Trojan in presence of sneak path in memristive nano crossbar circuits.

In the recent time due to advancement of technology, Malware and its clan have continued to advance and become more diverse. Malware otherwise Malicious Software consists of Virus, Trojan horse, Adware, Spyware etc. This said software leads to extrusion of data (Spyware), continuously flow of Ads (Adware), modifying or damaging the system files (Virus), or access of personal information (Trojan horse). Some of the major factors driving the growth of these attacks are due to poorly secured devices and the ease of availability of tools in the Internet with which anyone can attack any system. The attackers or the developers of Malware usually lean towards blending of malware into the executable file, which makes it hard to detect the presence of malware in executable files. In this paper we have done experimental study on various algorithms of Machine Learning for detecting the presence of Malware in executable files. After testing Naïve Bayes, KNN and SVM, we found out that SVM was the most suited algorithm and had the accuracy of 94%. We then created a web application where the user could upload executable file and test the authenticity of the said executable file if it is a Malware file or a benign file.

Recently, with the spread of Internet of Things (IoT) devices, embedded hardware devices have been used in a variety of everyday electrical items. Due to the increased demand for embedded hardware devices, some of the IC design and manufacturing steps have been outsourced to third-party vendors. Since malicious third-party vendors may insert malicious circuits, called hardware Trojans, into their products, developing an effective hardware Trojan detection method is strongly required. In this paper, we propose 25 hardware-Trojan features based on the structure of trigger circuits for machine-learning-based hardware Trojan detection. Combining the proposed features into 11 existing hardware-Trojan features, we totally utilize 36 hardware-Trojan features for classification. Then we classify the nets in an unknown netlist into a set of normal nets and Trojan nets based on the random-forest classifier. The experimental results demonstrate that the average true positive rate (TPR) becomes 63.6% and the average true negative rate (TNR) becomes 100.0%. They improve the average TPR by 14.7 points while keeping the average TNR compared to existing state-of-the-art methods. In particular, the proposed method successfully finds out Trojan nets in several benchmark circuits, which are not found by the existing method.

Machine learning and Artificial Intelligent techniques are the most used techniques. It gives opportunity to online sharing market where sharing and adopting model is being popular. It gives attackers many new opportunities. Deep neural network is the most used approached for artificial techniques. In this paper we are presenting a Proof of Concept method to detect Trojan attacks on the Deep Neural Network. Deploying trojan models can be dangerous in normal human lives (Application like Automated vehicle). First inverse the neuron network to create general trojan triggers, and then retrain the model with external datasets to inject Trojan trigger to the model. The malicious behaviors are only activated with the trojan trigger Input. In attack, original datasets are not required to train the model. In practice, usually datasets are not shared due to privacy or copyright concerns. We use five different applications to demonstrate the attack, and perform an analysis on the factors that affect the attack. The behavior of a trojan modification can be triggered without affecting the test accuracy for normal input datasets. After generating the trojan trigger and performing an attack. It's applying SHAP as defense against such attacks. SHAP is known for its unique explanation for model predictions.

Privacy and security have become the most important aspects in any sphere of technology today from embedded systems to VLS I circuits. One such an attack compromising the privacy, security and trust of a networked control system by making them vulnerable to unauthorized access is the Hardware Trojan Horses. Even cryptographic algorithms whose purpose is to safeguard information are susceptible to these Trojan attacks. This paper discusses hybrid supervised machine learning models that predict with great accuracy whether the RSA asymmetric cryptosystem implemented in Atmel XMega microcontroller is Trojan-free (Golden) or Trojan-infected by analyzing the power profiles of the golden algorithm and trojan-infected algorithm. The power profiles are obtained using the ChipWhisperer Lite Board. The features selected from the power profiles are used to create datasets for the proposed hybrid models and train the proposed models using the 70/30 rule. The proposed hybrid models can be concluded that it has an accuracy of more than 88% irrespective of the Trojan types and size of the datasets.

Process variation is the critical issue in hardware Trojan detection. In the state-of-art works, ring oscillators are employed to address this problem. But ring oscillators are very sensitive to IR-drop effect, which exists ICs. In this paper, based on circuit theory, a IR-drop calibration method is proposed. The nominal power supply voltage and the others power supply voltage with a very small difference of the nominal power supply voltage are applied to the test chip. It is assumed that they have the same IR-drop $Δ$V. Combined with these measured data, the value of Vth + $Δ$V, can be obtained by mathematic analysis. The typical Vth from circuit simulation is used to compute $Δ$V. We studied the proposed method in a tested chip.

Over the past few years, malicious hardware modifications, a.k.a. hardware Trojans (HT), have emerged as a major security threat because integrated circuit (IC) companies have been fabricating chips at offshore foundries due to various factors including time-to-market, cost reduction demands, and the increased complexity of ICs. Among proposed hardware Trojan detection techniques, reverse engineering appears to be the most accurate and reliable one because it works for all circuits and Trojan types without a golden example of the chip. However, because reverse engineering is an extremely expensive, time-consuming, and destructive process, it is difficult to apply this technique for a large population of ICs in a real test environment. This paper proposes a novel golden-chip-free clustering method using backscattering side-channel to divide ICs into groups of Trojan-free and Trojan-infected boards. The technique requires no golden chip or a priori knowledge of the chip circuitry, and divides a large population of ICs into clusters based on how HTs (if existed) affect their backscattered signals. This significantly reduces the size of test vectors for reverse engineering based detection techniques, thus enables deployment of reverse engineering approaches to a large population of ICs in a real testing scenario. The results are collected on 100 different FPGA boards where boards are randomly chosen to be infected or not. The results show that we can cluster the boards with 100% accuracy and demonstrate that our technique can tolerate manufacturing variations among hardware instances to cluster all the boards accurately for 9 different dormant Trojan designs on 3 different benchmark circuits from Trusthub. We have also shown that we can detect dormant Trojan designs whose trigger size has shrunk to as small as 0.19% of the original circuit with 100% accuracy as well.

The security of integrated circuits (IC) plays a very significant role on military, economy, communication and other industries. Due to the globalization of the integrated circuit (IC) from design to manufacturing process, the IC chip is vulnerable to be implanted malicious circuit, which is known as hardware Trojan (HT). When the HT is activated, it will modify the functionality, reduce the reliability of IC, and even leak confidential information about the system and seriously threatens national security. The HT detection theory and method is hotspot in the security of integrated circuit. However, most methods are focusing on the simulated data. Moreover, the measurement data of the real circuit are greatly affected by the measurement noise and process disturbances and few methods are available with small size of the Trojan circuit. In this paper, the problem of detection was cast as signal representation among multiple linear regression and sparse representation-based classifier (SRC) were first applied for Trojan detection. We assume that the training samples from a single class do lie on a subspace, and the test samples can be represented by the single class. The proposed SRC HT detection method on real integrated circuit shows high accuracy and efficiency.

Hardware security has long been an important issue in the current IC design. In this paper, a hardware Trojan detection method based on frequency domain characteristics of power consumption is proposed. For some HTs, it is difficult to detect based on the time domain characteristics, these types of hardware Trojan can be analyzed in the frequency domain, and Mahalanobis distance is used to classify designs with or without HTs. The experimental results demonstrate that taking 10% distance as the criterion, the hardware Trojan detection results in the frequency domain have almost no failure cases in all the tested designs.

This paper uses side channel analysis to detect hardware Trojan based on back propagation neural network. First, a power consumption collection platform is built to collect power waveforms, and the amplifier is utilized to amplify power consumption information to improve the detection accuracy. Then the small difference between the power waveforms is recognized by the back propagation neural network to achieve the purpose of detection. This method is validated on Advanced Encryption Standard circuit. Results show this method is able to identify the circuits with a Trojan occupied 0.19% of Advanced Encryption Standard circuit. And the detection accuracy rate can reach 100%.

This work proposes a plausible detection scheme for Hardware Trojan (HT) detection in frequency domain analysis. Due to shrinking technology every node consumes low power values (in the range of $μ$W) which are difficult to manipulate for HT detection using conventional methods. The proposed method utilizes the time domain power signals which is converted to frequency domain that represents the implausible signals and analyzed. The precision of HT detection is found to be increased because of the magnified power values in frequency domain. This work uses ISCAS89 bench mark circuits for conducting experiments. In this, the wide range of power values that spans from 695 $μ$W to 22.3 $μ$W are observed in frequency domain whereas the respective powers in time domain have narrow span of 2.29 $μ$W to 0.783 $μ$W which is unconvincing. This work uses the wide span of power values to identify HT and observed that the mid-band of frequencies have larger footprints than the side bands. These methods intend to help the designers in easy identification of HT even of single gate events.

At present, most Trojan detection methods are based on the features of host and code. Such methods have certain limitations and lag. This paper analyzes the network behavior features and network traffic of several typical Trojans such as Zeus and Weasel, and proposes a Trojan traffic detection algorithm based on machine learning. First, model different machine learning algorithms and use Random Forest algorithm to extract features for Trojan behavior and communication features. Then identify and detect Trojans' traffic. The accuracy is as high as 95.1%. Comparing the detection of different machine learning algorithms, experiments show that our algorithm has higher accuracy, which is helpful and useful for identifying Trojan.

Hardware Trojan war is expanding from digital world to analog domain. Although hardware Trojans in digital integrated circuits have been extensively investigated, there still lacks study on the Trojans crossing the boundary between digital and analog worlds. This work uses Inter-integrated Circuit (I2C) as an example to demonstrate the potential security threats on its master-slave interface. Furthermore, an obfuscated Trojan detection method is proposed to monitor the abnormal behaviors induced by analog Trojans on the I2C interface. Experimental results confirm that the proposed method has a high sensitivity to the compromised clock signal and can mitigate the clock mute attack with a success rate of over 98%.

Real-time clock circuits are widely used in modern electronic systems to provide time information to the systems at the beginning of the system power-on. In this paper, we present two types of Hardware Trojan designs that employ the time information as the trigger conditions. One is a real-time based Trojan, which will attack a system at some specific realworld time. The other is a relative-time based Trojan, which will be triggered when a specific time period passes after the system is powered on. In either case when a Trojan is triggered its payload may corrupt the system or leakage internal information to the outside world. Experimental results show that the extra power consumption, area overhead and delay time are all quite small and thus the detection of the Trojans is difficult by using traditional side-channel detection methods.

The rapid growth and globalization of the integrated circuit (IC) industry put the threat of hardware Trojans (HTs) front and center among all security concerns in the IC supply chain. Current Trojan detection approaches always assume HTs are composed of digital circuits. However, recent demonstrations of analog attacks, such as A2 and Rowhammer, invalidate the digital assumption in previous HT detection or testing methods. At the system level, attackers can utilize the analog properties of the underlying circuits such as charge-sharing and capacitive coupling effects to create information leakage paths. These new capacitor-based vulnerabilities are rarely covered in digital testings. To address these stealthy yet harmful threats, we identify a large class of such capacitor-enabled attacks and define them as charge-domain Trojans. We are able to abstract the detailed charge-domain models for these Trojans and expose the circuit-level properties that critically contribute to their information leakage paths. Aided by the abstract models, an information flow tracking (IFT) based solution is developed to detect charge-domain leakage paths and then identify the charge-domain Trojans/vulnerabilities. Our proposed method is validated on an experimental RISC microcontroller design injected with different variants of charge-domain Trojans. We demonstrate that successful detection can be accomplished with an automatic tool which realizes the IFT-based solution.

Hardware Trojans are malicious modifications on integrated circuits (IC), which pose a grave threat to the security of modern military and commercial systems. Existing methods of detecting hardware Trojans are plagued by the inability of detecting all Trojans, reliance on golden chip that might not be available, high time cost, and low accuracy. In this paper, we present Golden Gates, a novel detection method designed to achieve a comparable level of accuracy to full reverse engineering, yet paying only a fraction of its cost in time. The proposed method inserts golden gate circuits (GGC) to achieve superlative accuracy in the classification of all existing gate footprints using rapid scanning electron microscopy (SEM) and backside ultra thinning. Possible attacks against GGC as well as malicious modifications on interconnect layers are discussed and addressed with secure built-in exhaustive test infrastructure. Evaluation with real SEM images demonstrate high classification accuracy and resistance to attacks of the proposed technique.

Nowadays due to economic reasons most of the semiconductor companies prefer to outsource the manufacturing part of their designs to third fabrication foundries, the so-called fabs. Untrustworthy fabs can extract circuit blocks, the called intellectual properties (IPs), from the layouts and then pirate them. Such fabs are suspected of hardware Trojan (HT) threat in which malicious circuits are added to the layouts for sabotage objectives. HTs lead up to increase power consumption in HT-infected circuits. However, due to process variations, the power of HTs including few gates in million-gate circuits is not detectable in power consumption analysis (PCA). Thus, such circuits should be considered as a collection of small sub-circuits, and PCA must be individually performed for each one of them. In this article, we introduce an approach facilitating PCA-based HT detection methods. Concerning this approach, we propose a new logic locking method and algorithm. Logic locking methods and algorithm are usually employed against IP piracy. They modify circuits such that they do not correctly work without applying a correct key to. Our experiments at the gate level and post-synthesis show that the proposed locking method and algorithm increase the proportion of HT activity and consequently HT power to circuit power.

With the globalization of integrated circuit (IC) design and manufacturing, malicious third-party vendors can easily insert hardware Trojans into their intellect property (IP) cores during IC design phase, threatening the security of IC systems. It is strongly required to develop hardware-Trojan detection methods especially for the IC design phase. As the particularity of Trigger nets in Trojan circuits, in this paper, we propose an ensemble-learning-based hardware-Trojan detection method by detecting the Trigger nets at the gate level. We extract the Trigger-net features for each net from known netlists and use the ensemble learning method to train two detection models according to the Trojan types. The detection models are used to identify suspicious Trigger nets in an unknown detected netlist and give results of suspiciousness values for each detected net. By flagging the top n% suspicious nets of each detection model as the suspicious Trigger nets based on the suspiciousness values, the proposed method can achieve, on average, 88% true positive rate, 90% true negative rate, and 90% Accuracy.