Biblio

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%.

Electromagnetic (EM) radiation is an inherent phenomenon in the operation of electronic information equipment. The side-channel attack, malicious hardware and software implantation attack by using the EM radiation are implemented to steal information. This form of attacks can be used in air-gap information equipment, which bring great danger for information security. The malicious implantation hidden in circuits are difficult to detect. How to detect the implantation is a challenging problem. In this paper, a malicious hardware implantation is analyzed. A method that leverages EM signals for Trojan-embedded computer video cable detection is proposed. The method neither needs activating the Trojan nor requires near-field probe approaching at close. It utilizes recognizable patterns in the spectrum of EM to predict potential risks. This paper focuses on the extraction of feature vectors via the empirical mode decomposition (EMD) algorithm. Intrinsic mode functions (IMFs) are analyzed and selected to be eigenvectors. Using a common classification technique, we can achieve both effective and reliable detection results.

In recent years, integrated circuits (ICs) have become significant for various industries and their security has been given greater priority, specifically in the supply chain. Budgetary constraints have compelled IC designers to offshore manufacturing to third-party companies. When the designer gets the manufactured ICs back, it is imperative to test for potential threats like hardware trojans (HT). In this paper, a novel multi-level game-theoretic framework is introduced to analyze the interactions between a malicious IC manufacturer and the tester. In particular, the game is formulated as a non-cooperative, zero-sum, repeated game using prospect theory (PT) that captures different players' rationalities under uncertainty. The repeated game is separated into a learning stage, in which the defender learns about the attacker's tendencies, and an actual game stage, where this learning is used. Experiments show great incentive for the attacker to deceive the defender about their actual rationality by "playing dumb" in the learning stage (deception). This scenario is captured using hypergame theory to model the attacker's view of the game. The optimal deception rationality of the attacker is analytically derived to maximize utility gain. For the defender, a first-step deception mitigation process is proposed to thwart the effects of deception. Simulation results show that the attacker can profit from the deception as it can successfully insert HTs in the manufactured ICs without being detected.

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.

Hardware Trojan Horses and active fault attacks are a threat to the safety and security of electronic systems. By such manipulations, an attacker can extract sensitive information or disturb the functionality of a device. Therefore, several protections against malicious inclusions have been devised in recent years. A prominent technique to detect abnormal behavior in the field is run-time verification. It relies on dedicated monitoring circuits and on verification rules generated from a set of temporal properties. An important question when dealing with such protections is the effectiveness of the protection against unknown attacks. In this paper, we present a methodology based on automatic generation of monitoring and formal verification techniques that can be used to validate and analyze the quality of a set of temporal properties when used as protection against generic attackers of variable strengths.

With the application of integrated circuits (ICs) appears in all aspects of life, whether an IC is security and reliable has caused increasing worry which is of significant necessity. An attacker can achieve the malicious purpose by adding or removing some modules, so called hardware Trojans (HTs). In this paper, we use side-channel analysis (SCA) and support vector machine (SVM) classifier to determine whether there is a Trojan in the circuit. We use SAKURA-G circuit board with Xilinx SPARTAN-6 to complete our experiment. Results show that the Trojan detection rate is up to 93% and the classification accuracy is up to 91.8475%.

Hardware Trojans, implantable at a myriad of points within the supply chain, are difficult to detect and identify. By emulating systems on programmable hardware, the authors have created a tool from which to create and evaluate Trojan attack signatures and therefore enable better Trojan detection (for in-service systems) and prevention (for in-design systems).

The outsourcing for fabrication introduces security threats, namely hardware Trojans (HTs). Many design-for-trust (DFT) techniques have been proposed to address such threats. However, many HT detection techniques are not effective due to the dependence on golden chips, limitation of useful information available and process variations. In this paper, we data-mine on path delay information and propose a variation-tolerant path delay order encoding technique to detect HTs.

Integrated circuits (ICs) are becoming vulnerable to hardware Trojans. Most of existing works require golden chips to provide references for hardware Trojan detection. However, a golden chip is extremely difficult to obtain. In previous work, we have proposed a classification-based golden chips-free hardware Trojan detection technique. However, the algorithm in the previous work are trained by simulated ICs without considering that there may be a shift which occurs between the simulation and the silicon fabrication. It is necessary to learn from actual silicon fabrication in order to obtain an accurate and effective classification model. We propose a co-training based hardware Trojan detection technique exploiting unlabeled fabricated ICs and inaccurate simulation models, to provide reliable detection capability when facing fabricated ICs, while eliminating the need of fabricated golden chips. First, we train two classification algorithms using simulated ICs. During test-time, the two algorithms can identify different patterns in the unlabeled ICs, and thus be able to label some of these ICs for the further training of the another algorithm. Moreover, we use a statistical examination to choose ICs labeling for the another algorithm in order to help prevent a degradation in performance due to the increased noise in the labeled ICs. We also use a statistical technique for combining the hypotheses from the two classification algorithms to obtain the final decision. The theoretical basis of why the co-training method can work is also described. Experiment results on benchmark circuits show that the proposed technique can detect unknown Trojans with high accuracy (92% 97%) and recall (88% 95%).

Hardware Trojans (HTs) are malicious modifications of the original circuits intended to leak information or cause malfunction. Based on the Side Channel Analysis (SCA) technology, a set of hardware Trojan detection platform is designed for RTL circuits on the basis of HSPICE power consumption simulation. Principal Component Analysis (PCA) algorithm is used to reduce the dimension of power consumption data. An intelligent neural networks (NN) algorithm based on Particle Swarm Optimization (PSO) is introduced to achieve HTs recognition. Experimental results show that the detection accuracy of PSO NN method is much better than traditional BP NN method.

As a result of the globalization of integrated circuits (ICs) design and fabrication process, ICs are becoming vulnerable to hardware Trojans. Most of the existing hardware Trojan detection works suppose that the testing stage is trustworthy. However, testing parties may conspire with malicious attackers to modify the results of hardware Trojan detection. In this paper, we propose a trusted and robust hardware Trojan detection framework against untrustworthy testing parties exploiting a novel clustering ensemble method. The proposed technique can expose the malicious modifications on Trojan detection results introduced by untrustworthy testing parties. Compared with the state-of-the-art detection methods, the proposed technique does not require fabricated golden chips or simulated golden models. The experiment results on ISCAS89 benchmark circuits show that the proposed technique can resist modifications robustly and detect hardware Trojans with decent accuracy (up to 91%).

The globalization and outsourcing of the semiconductor industry has raised serious concerns about the trustworthiness of the hardware. Importing Third Party IP cores in the Integrated Chip design has opened gates for new form of attacks on hardware. Hardware Trojans embedded in Third Party IPs has necessitated the need for secure IC design process. Design-for-Trust techniques aimed at detection of Hardware Trojans come with overhead in terms of area, latency and power consumption. In this work, we present a Cuckoo Search algorithm based Design Space Exploration process for finding low cost hardware solutions during High Level Synthesis. The exploration is conducted with respect to datapath resource allocation for single and nested loops. The proposed algorithm is compared with existing Hardware Trojan detection mechanisms and experimental results show that the proposed algorithm is able to achieve 3x improvement in Cost when compared existing algorithms.

Due to the increase in design complexity and cost of VLSI chips, a number of design houses outsource manufacturing and import designs in a way to reduce the cost. This results in a decrease of the authenticity and security of the manufactured product. Since product development involves outside sources, circuit designers can not guarantee that their hardware has not been altered. It is often possible that attackers include additional hardware in order to gain privileges over the original circuit or cause damage to the product. These added circuits are called ``Hardware Trojans''. In this paper, we investigate introducing necessary modules needed for detection of hardware Trojans. We also introduce necessary programmable logic fabric that can be used in the implementation of the hardware assertion checkers. Our target is to utilize the provided programable fabric in a System on Chip (SoC) and optimize the hardware assertion to cover the detection of most hardware trojans in each core of the target SoC.

Hardware Trojan (HT) detection methods based on the side channel analysis deeply suffer from the process variations. In order to suppress the effect of the variations, we devise a method that smartly selects two highly correlated paths for each interconnect (edge) that is suspected to have an HT on it. First path is the shortest one passing through the suspected edge and the second one is a path that is highly correlated with the first one. Delay ratio of these paths avails the detection of the HT inserted circuits. Test results reveal that the method enables the detection of even the minimally invasive Trojans in spite of both inter and intra die variations with the spatial correlations.

High detection sensitivity in the presence of process variation is a key challenge for hardware Trojan detection through side channel analysis. In this work, we present an efficient Trojan detection approach in the presence of elevated process variations. The detection sensitivity is sharpened by 1) comparing power levels from neighboring regions within the same chip so that the two measured values exhibit a common trend in terms of process variation, and 2) generating test patterns that toggle each cell multiple times to increase Trojan activation probability. Detection sensitivity is analyzed and its effectiveness demonstrated by means of RPD (relative power difference). We evaluate our approach on ISCAS'89 and ITC'99 benchmarks and the AES-128 circuit for both combinational and sequential type Trojans. High detection sensitivity is demonstrated by analysis on RPD under a variety of process variation levels and experiments for Trojan inserted circuits.

With the globalization of integrated circuit design and manufacturing, Hardware Trojan have posed serious threats to the security of commercial chips. In this paper, we propose the framework of two-level temperature difference based thermal map analysis detection method. In our proposed method, thermal maps of an operating chip during a period are captured, and they are differentiated with the thermal maps of a golden model. Then every pixel's differential temperature of differential thermal maps is extracted and compared with other pixel's. To mitigate the Gaussian white noise and to differentiate the information of Hardware Trojan from the information of normal circuits, Kalman filter algorithm is involved. In our experiment, FPGAs configured with equivalent circuits are utilized to simulate the real chips to validate our proposed approach. The experimental result reveals that our proposed framework can detect Hardware Trojan whose power proportion magnitude is 10''3.

Hardware Trojan detection has emerged as a critical challenge to ensure security and trustworthiness of integrated circuits. A vast majority of research efforts in this area has utilized side-channel analysis for Trojan detection. Functional test generation for logic testing is a promising alternative but it may not be helpful if a Trojan cannot be fully activated or the Trojan effect cannot be propagated to the observable outputs. Side-channel analysis, on the other hand, can achieve significantly higher detection coverage for Trojans of all types/sizes, since it does not require activation/propagation of an unknown Trojan. However, they have often limited effectiveness due to poor detection sensitivity under large process variations and small Trojan footprint in side-channel signature. In this paper, we address this critical problem through a novel side-channel-aware test generation approach, based on a concept of Multiple Excitation of Rare Switching (MERS), that can significantly increase Trojan detection sensitivity. The paper makes several important contributions: i) it presents in detail the statistical test generation method, which can generate high-quality testset for creating high relative activity in arbitrary Trojan instances; ii) it analyzes the effectiveness of generated testset in terms of Trojan coverage; and iii) it describes two judicious reordering methods can further tune the testset and greatly improve the side channel sensitivity. Simulation results demonstrate that the tests generated by MERS can significantly increase the Trojans sensitivity, thereby making Trojan detection effective using side-channel analysis.

A hardware Trojan (HT) detection method is presented that is based on measuring and detecting small systematic changes in path delays introduced by capacitive loading effects or series inserted gates of HTs. The path delays are measured using a high resolution on-chip embedded test structure called a time-to-digital converter (TDC) that provides approx. 25 ps of timing resolution. A calibration method for the TDC as well as a chip-averaging technique are demonstrated to nearly eliminate chip-to-chip and within-die process variation effects on the measured path delays across chips. This approach significantly improves the correlation between Trojan-free chips and a simulation-based golden model. Path delay tests are applied to multiple copies of a 90nm custom ASIC chip having two copies of an AES macro. The AES macros are exact replicas except for the insertion of several additional gates in the second hardware copy, which are designed to model HTs. Simple statistical detection methods are used to isolate and detect systematic changes introduced by these additional gates. We present hardware results which demonstrate that our proposed chip-averaging and calibration techniques in combination with a single nominal simulation model can be used to detect small delay anomalies introduced by the inserted gates of hardware Trojans.

Hardware Trojan detection has emerged as a critical challenge to ensure security and trustworthiness of integrated circuits. A vast majority of research efforts in this area has utilized side-channel analysis for Trojan detection. Functional test generation for logic testing is a promising alternative but it may not be helpful if a Trojan cannot be fully activated or the Trojan effect cannot be propagated to the observable outputs. Side-channel analysis, on the other hand, can achieve significantly higher detection coverage for Trojans of all types/sizes, since it does not require activation/propagation of an unknown Trojan. However, they have often limited effectiveness due to poor detection sensitivity under large process variations and small Trojan footprint in side-channel signature. In this paper, we address this critical problem through a novel side-channel-aware test generation approach, based on a concept of Multiple Excitation of Rare Switching (MERS), that can significantly increase Trojan detection sensitivity. The paper makes several important contributions: i) it presents in detail the statistical test generation method, which can generate high-quality testset for creating high relative activity in arbitrary Trojan instances; ii) it analyzes the effectiveness of generated testset in terms of Trojan coverage; and iii) it describes two judicious reordering methods can further tune the testset and greatly improve the side channel sensitivity. Simulation results demonstrate that the tests generated by MERS can significantly increase the Trojans sensitivity, thereby making Trojan detection effective using side-channel analysis.

The use of side-channel measurements and fingerprinting, in conjunction with statistical analysis, has proven to be the most effective method for accurately detecting hardware Trojans in fabricated integrated circuits. However, these post-fabrication trust evaluation methods overlook the capabilities of advanced design skills that attackers can use in designing sophisticated Trojans. To this end, we have designed a Trojan using power-gating techniques and demonstrate that it can be masked from advanced side-channel fingerprinting detection while dormant. We then propose a real-time trust evaluation framework that continuously monitors the on-board global power consumption to monitor chip trustworthiness. The measurements obtained corroborate our frameworks effectiveness for detecting Trojans. Finally, the results presented are experimentally verified by performing measurements on fabricated Trojan-free and Trojan-infected variants of a reconfigurable linear feedback shift register (LFSR) array.

The detectability of malicious circuitry on FPGAs with varying placement properties yet has to be investigated. The authors utilize a Xilinx Virtex-II Pro target platform in order to insert a sequential denial-of-service Trojan into an existing AES design by manipulating a Xilinx-specific, intermediate file format prior to the bitstream generation. Thereby, there is no need for an attacker to acquire access to the hardware description language representation of a potential target architecture. Using a side-channel analysis setup for electromagnetic emanation (EM) measurements, they evaluate the detectability of different Trojan designs with varying location and logic distribution properties. The authors successfully distinguish the malicious from the genuine designs and provide information on how the location and distribution properties of the Trojan logic affect its detectability. To the best of their knowledge, this has been the first practically conducted Trojan detection using localized EM measurements.
 

This paper discusses the detection of hardware Trojans (HTs) by their breaking of symmetries within integrated circuits (ICs), as measured by path delays. Typically, path delay or side channel methods rely on comparisons to a golden, or trusted, sample. However, golden standards are affected by inter-and intra-die variations which limit the confidence in such comparisons. Symmetry is a way to detect modifications to an IC with increased confidence by confirming subcircuit consistencies within as it was originally designed. The difference in delays from a given path to a set of symmetric paths will be the same unless an inserted HT breaks symmetry. Symmetry can naturally exist in ICs or be artificially added. We describe methods to find and measure path delays against symmetric paths, as well as the advantages and disadvantages of this method. We discuss results of examples from benchmark circuits demonstrating the detection of hardware Trojans.
 

Detecting hardware Trojan is a difficult task in general. The context is that of a fabless design house that sells IP blocks as GDSII hard macros, and wants to check that final products have not been infected by Trojan during the foundry stage. In this paper we analyzed hardware Trojan horses insertion and detection in Scalable Encryption Algorithm (SEA) crypto. We inserted Trojan at different levels in the ASIC design flow of SEA crypto and most importantly we focused on Gate level and layout level Trojan insertions. We choose path delays in order to detect Trojan at both levels in design phase. Because the path delays detection technique is cost effective and efficient method to detect Trojan. The comparison of path delays makes small Trojan circuits significant from a delay point of view. We used typical, fast and slow 90nm libraries in order to estimate the efficiency of path delay technique in different operating conditions. The experiment's results show that the detection rate on payload Trojan is 100%.