Biblio
Intellectual property (IP) and integrated circuit (IC) piracy are of increasing concern to IP/IC providers because of the globalization of IC design flow and supply chains. Such globalization is driven by the cost associated with the design, fabrication, and testing of integrated circuits and allows avenues for piracy. To protect the designs against IC piracy, we propose a fingerprinting scheme based on side-channel power analysis and machine learning methods. The proposed method distinguishes the ICs which realize a modified netlist, yet same functionality. Our method doesn't imply any hardware overhead. We specifically focus on the ability to detect minimal design variations, as quantified by the number of logic gates changed. Accuracy of the proposed scheme is greater than 96 percent, and typically 99 percent in detecting one or more gate-level netlist changes. Additionally, the effect of temperature has been investigated as part of this work. Results depict 95.4 percent accuracy in detecting the exact number of gate changes when data and classifier use the same temperature, while training with different temperatures results in 33.6 percent accuracy. This shows the effectiveness of building temperature-dependent classifiers from simulations at known operating temperatures.
Reconfigurable Scan Networks (RSNs) are a powerful tool for testing and maintenance of embedded systems, since they allow for flexible access to on-chip instrumentation such as built-in self-test and debug modules. RSNs, however, can be also exploited by malicious users as a side-channel in order to gain information about sensitive data or intellectual property and to recover secret keys. Hence, implementing appropriate counter-measures to secure the access to and data integrity of embedded instrumentation is of high importance. In this paper we present a novel hardware and software combined approach to ensure data privacy in IEEE Std 1687 (IJTAG) RSNs. To do so, both a secure IJTAG compliant plug-and-play instrument wrapper and a versatile software toolchain are introduced. The wrapper demonstrates the necessary architectural adaptations required when using a lightweight stream cipher, whereas the software toolchain provides a seamless integration of the testing workflow with stream cipher. The applicability of the method is demonstrated by an FPGA-based implementation. We report on the performance of the developed instrument wrapper, which is empirically shown to have only a small impact on the workflow in terms of hardware overhead, operational costs and test time overhead.
In VLSI industry the design cycle is categorized into Front End Design and Back End Design. Front End Design flow is from Specifications to functional verification of RTL design. Back End Design is from logic synthesis to fabrication of chip. Handheld devices like Mobile SOC's is an amalgamation of many components like GPU, camera, sensor, display etc. on one single chip. In order to integrate these components protocols are needed. One such protocol in the emerging trend is I3C protocol. I3C is abbreviated as Improved Inter Integrated Circuit developed by Mobile Industry Processor Interface (MIPI) alliance. Most probably used for the interconnection of sensors in Mobile SOC's. The main motivation of adapting the standard is for the increase speed and low pin count in most of the hardware chips. The bus protocol is backward compatible with I2C devices. The paper includes detailed study I3C bus protocol and developing verification environment for the protocol. The test bench environment is written and verified using system Verilog and UVM. The Universal Verification Methodology (UVM) is base class library built using System Verilog which provides the fundamental blocks needed to quickly develop reusable and well-constructed verification components and test environments. The Functional Coverage of around 93.55 % and Code Coverage of around 98.89 % is achieved by verification closure.
Scan design is a universal design for test (DFT) technology to increase the observability and controllability of the circuits under test by using scan chains. However, it also leads to a potential security problem that attackers can use scan design as a backdoor to extract confidential information. Researchers have tried to address this problem by using secure scan structures that usually have some keys to confirm the identities of users. However, the traditional methods to store intermediate data or keys in memory are also under high risk of being attacked. In this paper, we propose a dynamic-key secure DFT structure that can defend scan-based and memory attacks without decreasing the system performance and the testability. The main idea is to build a scan design key generator that can generate the keys dynamically instead of storing and using keys in the circuit statically. Only specific patterns derived from the original test patterns are valid to construct the keys and hence the attackers cannot shift in any other patterns to extract correct internal response from the scan chains or retrieve the keys from memory. Analysis results show that the proposed method can achieve a very high security level and the security level will not decrease no matter how many guess rounds the attackers have tried due to the dynamic nature of our method.
A hardware Trojan (HT) denotes the malicious addition or modification of circuit elements. The purpose of this work is to improve the HT detection sensitivity in ICs using power side-channel analysis. This paper presents three detection techniques in power based side-channel analysis by increasing Trojan-to-circuit power consumption and reducing the variation effect in the detection threshold. Incorporating the three proposed methods has demonstrated that a realistic fine-grain circuit partitioning and an improved pattern set to increase HT activation chances can magnify Trojan detectability.
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%).
Pre-Silicon hardware Trojan detection has been studied for years. The most popular benchmark circuits are from the Trust-Hub. Their common feature is that the probability of activating hardware Trojans is very low. This leads to a series of machine learning based hardware Trojan detection methods which try to find the nets with low signal probability of 0 or 1. On the other hand, it is considered that, if the probability of activating hardware Trojans is high, these hardware Trojans can be easily found through behaviour simulations or during functional test. This paper explores the "grey zone" between these two opposite scenarios: if the activation probability of a hardware Trojan is not low enough for machine learning to detect it and is not high enough for behaviour simulation or functional test to find it, it can escape from detection. Experiments show the existence of such hardware Trojans, and this paper suggests a new set of hardware Trojan benchmark circuits for future study.
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.
The accessibility of on-chip embedded infrastructure for test, reconfiguration, or debug poses a serious security problem. Access mechanisms based on IEEE Std 1149.1 (JTAG), and especially reconfigurable scan networks (RSNs), as allowed by IEEE Std 1500, IEEE Std 1149.1-2013, and IEEE Std 1687 (IJTAG), require special care in the design and development. This work studies the threats to trustworthy data transmission in RSNs posed by untrusted components within the RSN and external interfaces. We propose a novel scan pattern generation method that finds trustworthy access sequences to prevent sniffing and spoofing of transmitted data in the RSN. For insecure RSNs, for which such accesses do not exist, we present an automated transformation that improves the security and trustworthiness while preserving the accessibility to attached instruments. The area overhead is reduced based on results from trustworthy access pattern generation. As a result, sensitive data is not exposed to untrusted components in the RSN, and compromised data cannot be injected during trustworthy accesses.
Scan-based test is commonly used to increase testability and fault coverage, however, it is also known to be a liability for chip security. Research has shown that intellectual property (IP) or secret keys can be leaked through scan-based attacks. In this paper, we propose a dynamically-obfuscated scan design for protecting IPs against scan-based attacks. By perturbing all test patterns/responses and protecting the obfuscation key, the proposed architecture is proven to be robust against existing non-invasive scan attacks, and can protect all scan data from attackers in foundry, assembly, and system developers (i.e., OEMs) without compromising the testability. Furthermore, the proposed architecture can be easily plugged into EDA generated scan chains without having a noticeable impact on conventional integrated circuit (IC) design, manufacturing, and test flow. Finally, detailed security and experimental analyses have been performed on several benchmarks. The results demonstrate that the proposed method can protect chips from existing brute force, differential, and other scan-based attacks that target the obfuscation key. The proposed design is of low overhead on area, power consumption, and pattern generation time, and there is no impact on test time.
Hardware Trojans are an emerging threat that intrudes in the design and manufacturing cycle of the chips and has gained much attention lately due to the severity of the problems it draws to the chip supply chain. Hardware Typically, hardware Trojans are not detected during the usual manufacturing testing due to the fact that they are activated as an effect of a rare event. A class of published HTs are based on the geometrical characteristics of the circuit and claim to be undetectable, in the sense that their activation cannot be detected. In this work we study the effect of continuously monitoring the inputs of the module under test with respect to the detection of HTs possibly inserted in the module, either in the design or the manufacturing stage.
This brief proposes a framework to analyze multiple faults based on multiple fault simulation in a particle swarm optimization environment. Experimentation shows that up to ten faults can be diagnosed in a reasonable time. However, the scheme does not put any restriction on the number of simultaneous faults.
Defects cluster, and the probability of a multiple fault is significantly higher than just the product of the single fault probabilities. While this observation is beneficial for high yield, it complicates fault diagnosis. Multiple faults will occur especially often during process learning, yield ramp-up and field return analysis. In this paper, a logic diagnosis algorithm is presented which is robust against multiple faults and which is able to diagnose multiple faults with high accuracy even on compressed test responses as they are produced in embedded test and built-in self-test. The developed solution takes advantage of the linear properties of a MISR compactor to identify a set of faults likely to produce the observed faulty signatures. Experimental results show an improvement in accuracy of up to 22 % over traditional logic diagnosis solutions suitable for comparable compaction ratios.
The migration from a vertical to horizontal business model has made it easier to introduce hardware Trojans and counterfeit electronic parts into the electronic component supply chain. Hardware Trojans are malicious modifications made to original IC designs that reduce system integrity (change functionality, leak private data, etc.). Counterfeit parts are often below specification and/or of substandard quality. The existence of Trojans and counterfeit parts creates risks for the life-critical systems and infrastructures that incorporate them including automotive, aerospace, military, and medical systems. In this tutorial, we will cover: (i) Background and motivation for hardware Trojan and counterfeit prevention/detection; (ii) Taxonomies related to both topics; (iii) Existing solutions; (iv) Open challenges; (v) New and unified solutions to address these challenges.