Biblio

Hardware IPs are assumed to be roots-of-trust in complex SoCs. However, their design and security verification are still heavily dependent on manual expertise. Extensive research in this domain has shown that even cryptographic modules may lack information flow security, making them susceptible to remote attacks. Further, when an SoC is in the hands of the attacker, physical attacks such as fault injection are possible. This paper introduces EISec, a novel tool utilizing symbolic execution for exhaustive analysis of hardware IPs. EISec operates at the pre-silicon stage on the gate level netlist of a design. It detects information flow security violations and generates the exhaustive set of control sequences that reproduces them. We further expand its capabilities to quantify the confusion and diffusion present in cryptographic modules and to analyze an FSM's susceptibility to fault injection attacks. The proposed methodology efficiently explores the complete input space of designs utilizing symbolic execution. In short, EISec is a holistic security analysis tool to help hardware designers capture security violations early on and mitigate them by reporting their triggers.

The Internet of Things (IoT) is transforming the way we live and work by increasing the connectedness of people and things on a scale that was once unimaginable. However, the vulnerabilities in the IoT supply chain have raised serious concerns about the security and trustworthiness of IoT devices and components within them. Testing for device provenance, detection of counterfeit integrated circuits (ICs) and systems, and traceability of IoT devices are challenging issues to address. In this article, we develop a novel radio-frequency identification (RFID)-based system suitable for counterfeit detection, traceability, and authentication in the IoT supply chain called CDTA. CDTA is composed of different types of on-chip sensors and in-system structures that collect necessary information to detect multiple counterfeit IC types (recycled, cloned, etc.), track and trace IoT devices, and verify the overall system authenticity. Central to CDTA is an RFID tag employed as storage and a channel to read the information from different types of chips on the printed circuit board (PCB) in both power-on and power-off scenarios. CDTA sensor data can also be sent to the remote server for authentication via an encrypted Ethernet channel when the IoT device is deployed in the field. A novel board ID generator is implemented by combining outputs of physical unclonable functions (PUFs) embedded in the RFID tag and different chips on the PCB. A light-weight RFID protocol is proposed to enable mutual authentication between RFID readers and tags. We also implement a secure interchip communication on the PCB. Simulations and experimental results using Spartan 3E FPGAs demonstrate the effectiveness of this system. The efficiency of the radio-frequency (RF) communication has also been verified via a PCB prototype with a printed slot antenna.

Modern embedded computing devices are vulnerable against malware and software piracy due to insufficient security scrutiny and the complications of continuous patching. To detect malicious activity as well as protecting the integrity of executable software, it is necessary to monitor the operation of such devices. In this paper, we propose a disassembler based on power-based side-channel to analyze the real-time operation of embedded systems at instruction-level granularity. The proposed disassembler obtains templates from an original device (e.g., IoT home security system, smart thermostat, etc.) and utilizes machine learning algorithms to uniquely identify instructions executed on the device. The feature selection using Kullback-Leibler (KL) divergence and the dimensional reduction using PCA in the time-frequency domain are proposed to increase the identification accuracy. Moreover, a hierarchical classification framework is proposed to reduce the computational complexity associated with large instruction sets. In addition, covariate shifts caused by different environmental measurements and device-to-device variations are minimized by our covariate shift adaptation technique. We implement this disassembler on an AVR 8-bit microcontroller. Experimental results demonstrate that our proposed disassembler can recognize test instructions including register names with a success rate no lower than 99.03% with quadratic discriminant analysis (QDA).

Hardware Trojan insertion and intellectual property (IP) theft are two major concerns when dealing with untrusted foundries. Most existing mitigation techniques are limited in protecting against both vulnerabilities. Split manufacturing is designed to stop IP piracy and IC cloning, but it fails at preventing untargeted hardware Trojan insertion and incurs significant overheads when high level of security is demanded. Built-in self-authentication (BISA) is a low cost technique for preventing and detecting hardware Trojan insertion, but is vulnerable to IP piracy, IC cloning or redesign attacks, especially on original circuitry. In this paper, we propose an obfuscated built-in self-authentication (OBISA) technique that combines and optimizes both technique so that they complement and improve security against both vulnerabilities. Performance of the proposed OBISA technique is presented with experimental implementation on same benchmark circuits as used in the existing wire lifting technique. The security performance is evaluated with the most popular split manufacturing security metrics.

In the era of globalized Integrated Circuit (IC) design and manufacturing flow, a rising issue to the silicon industry is various attacks on hardware intellectual property (IP). As a measure to ensure security along the supply chain against IP piracy, tampering and reverse engineering, hardware obfuscation is considered a reliable defense mechanism. Sequential and combinational obfuscations are the primary classes of obfuscation, and multiple methods have been proposed in each type in recent years. This paper presents an overview of obfuscation techniques and a qualitative comparison of the two major types.

We provide an analysis of IEEE standard P1735, which describes methods for encrypting electronic-design intellectual property (IP), as well as the management of access rights for such IP. We find a surprising number of cryptographic mistakes in the standard. In the most egregious cases, these mistakes enable attack vectors that allow us to recover the entire underlying plaintext IP. Some of these attack vectors are well-known, e.g. padding-oracle attacks. Others are new, and are made possible by the need to support the typical uses of the underlying IP; in particular, the need for commercial system-on-chip (SoC) tools to synthesize multiple pieces of IP into a fully specified chip design and to provide syntax errors. We exploit these mistakes in a variety of ways, leveraging a commercial SoC tool as a black-box oracle. In addition to being able to recover entire plaintext IP, we show how to produce standard-compliant ciphertexts of IP that have been modified to include targeted hardware Trojans. For example, IP that correctly implements the AES block cipher on all but one (arbitrary) plaintext that induces the block cipher to return the secret key. We outline a number of other attacks that the standard allows, including on the cryptographic mechanism for IP licensing. Unfortunately, we show that obvious "quick fixes" to the standard (and the tools that support it) do not stop all of our attacks. This suggests that the standard requires a significant overhaul, and that IP-authors using P1735 encryption should consider themselves at risk.

The rapid growth of Internet-of-things and other electronic devices make a huge impact on how and where data travel. The confidential data (e.g., personal data, financial information) that travel through unreliable channels can be exposed to attackers. In hardware, the confidential data such as secret cipher keys are facing the same issue. This problem is even more serious when the IP is from a 3rd party and contains scan-chains. Thus, data flow tracking is important to analyze possible leakage channels in fighting against such hardware security threats. This paper introduces a method for tracking data flow and detecting potential hardware Trojans in gate-level soft IPs using assets and Structural Checking tool.

A finite state machine (FSM) is responsible for controlling the overall functionality of most digital systems and, therefore, the security of the whole system can be compromised if there are vulnerabilities in the FSM. These vulnerabilities can be created by improper designs or by the synthesis tool which introduces additional don't-care states and transitions during the optimization and synthesis process. An attacker can utilize these vulnerabilities to perform fault injection attacks or insert malicious hardware modifications (Trojan) to gain unauthorized access to some specific states. To our knowledge, no systematic approaches have been proposed to analyze these vulnerabilities in FSM. In this paper, we develop a framework named Analyzing Vulnerabilities in FSM (AVFSM) which extracts the state transition graph (including the don't-care states and transitions) from a gate-level netlist using a novel Automatic Test Pattern Generation (ATPG) based approach and quantifies the vulnerabilities of the design to fault injection and hardware Trojan insertion. We demonstrate the applicability of the AVFSM framework by analyzing the vulnerabilities in the FSM of AES and RSA encryption module. We also propose a low-cost mitigation technique to make FSM more secure against these attacks.

With the advent of globalization in the semiconductor industry, it is necessary to prevent unauthorized usage of third-party IPs (3PIPs), cloning and unwanted modification of 3PIPs, and unauthorized production of ICs. Due to the increasing complexity of ICs, system-on-chip (SoC) designers use various 3PIPs in their design to reduce time-to-market and development costs, which creates a trust issue between the SoC designer and the IP owners. In addition, as the ICs are fabricated around the globe, the SoC designers give fabrication contracts to offshore foundries to manufacture ICs and have little control over the fabrication process, including the total number of chips fabricated. Similarly, the 3PIP owners lack control over the number of fabricated chips and/or the usage of their IPs in an SoC. Existing research only partially addresses the problems of IP piracy and IC overproduction, and to the best of our knowledge, there is no work that considers IP overuse. In this article, we present a comprehensive solution for preventing IP piracy and IC overproduction by assuring forward trust between all entities involved in the SoC design and fabrication process. We propose a novel design flow to prevent IC overproduction and IP overuse. We use an existing logic encryption technique to obfuscate the netlist of an SoC or a 3PIP and propose a modification to enable manufacturing tests before the activation of chips which is absolutely necessary to prevent overproduction. We have used asymmetric and symmetric key encryption, in a fashion similar to Pretty Good Privacy (PGP), to transfer keys from the SoC designer or 3PIP owners to the chips. In addition, we also propose to attach an IP digest (a cryptographic hash of the entire IP) to the header of an IP to prevent modification of the IP by the SoC designers. We have shown that our approach is resistant to various attacks with the cost of minimal area overhead.