We demonstrate a Hardware Trojan (HT)-based circuit-to-circuit attack mechanism in the context of Systems-on-Chip (SoCs). The HT trigger is hidden inside the attacking circuit and the HT payload travels from the attacking circuit to the victim circuit via the test infrastructure. The common test infrastructure is configured accordingly by the HT so as to propagate the HT payload. We demonstrate the capability of this HT to perform a denial-of-service attack on an industrial Analog-to-Digital Converter (ADC) connected to a IEEE 1687 test infrastructure.

Hardware Trojan (HT) insertion is a major security threat for electronic components that demand a high trust level. Several HT attack mechanisms have been demonstrated to date, and several HT prevention and detection countermeasures have been proposed to thwart HT attacks. Given the multitude of HT attack mechanisms, run-time monitors for HT detection are used as a last line of defense. In this paper, we propose a run-time monitoring methodology for HT attack mechanisms affecting the analog and mixed-signal (AMS) sections of an Integrated Circuit (IC). The methodology is based on the Symmetry-based Built-In Self-Test (SymBIST) principle that relies on distributing invariances across the IC and continuously checking for their compliance. Detection of various HT attacks are demonstrated on a Successive Approximation Register (SAR) Analog-to-Digital Converter (ADC) IP at transistor-level.

We propose a Hardware Trojan (HT) attack for analog circuits with its key characteristic being that it cannot be prevented or detected in the analog domain. The HT attack works in the context of Systems-on-Chip (SoCs) comprising both digital and analog Intellectual Property (IP) blocks. The attacker could be either the SoC integrator or the foundry. More specifically, the HT trigger is placed inside a dense digital IP block where it can be effectively hidden, whereas the HT payload is in the form of a digital pattern transported via the test bus or generated within the test bus, reaching the Design-for-Test (DfT) or programmability interface of the victim analog IP with the test bus. The HT payload unexpectedly activates the DfT and sets the victim analog IP into some possibly partial and undocumented test mode or changes the nominal programmability. The HT payload can be designed to result in performance degradation or complete malfunction, i.e., denial of service. We demonstrate this HT attack scenario on two analog IPs, namely a low-dropout (LDO) regulator using simulation and an RF receiver using hardware measurements.

Fault diagnosis methodologies for analog circuits lag far behind those for their digital counterparts. In this paper, we show how the generic Symmetry-based Built-In Self-Test (BIST) (or SymBIST), originally proposed for defect-oriented post-manufacturing test and on-line test, can be seamlessly reused for the purpose of diagnosis. BIST can offer better insights into the circuit and, thereby, can assist diagnosis towards resolving ambiguity groups. Using SymBIST we demonstrate high diagnosis resolution and fast diagnosis cycle for an industrial Successive Approximation Register (SAR) Analog-to-Digital Converter (ADC).

We propose a Built-In Self-Test (BIST) paradigm for analog and mixed-signal (A/M-S) Integrated Circuits (ICs), called symmetry-based BIST (SymBIST). SymBIST exploits inherent symmetries in an A/M-S IC to construct signals that are invariant by default, and subsequently checks those signals against a tolerance window. Violation of invariant properties points to the occurrence of a defect or abnormal operation. SymBIST is designed to serve as a functional safety mechanism. It is reusable ranging from post-manufacturing test, where it targets defect detection, to on-line test in the field of operation, where it targets low-latency detection of transient failures and degradation due to aging. We demonstrate SymBIST on a Successive Approximation Register (SAR) Analog-to-Digital Converter (ADC). SymBIST features high defect coverage, short test time, low overhead, zero performance penalty, and has a fully digital interface making it compatible with modern digital test access mechanisms.

In this paper, we propose a defect-oriented Built-In Self-Test (BIST) paradigm for analog and mixed-signal (A/MS) Integrated Circuits (ICs), called symmetry-based BIST (Sym-BIST). SymBIST exploits inherent symmetries into the design to generate invariances that should hold true only in defect-free operation. Violation of any of these invariances points to defect detection. We demonstrate SymBIST on a 65nm 10-bit Successive Approximation Register (SAR) Analog-to-Digital Converter (ADC) IP by ST Microelectronics.

We present a Hardware Trojan (HT) attack scenario for analog circuits. The characteristic of this HT is that it does not reside inside the victim analog circuit. Instead, it resides on an independent digital circuit on the same die where it is triggered, yet its payload is applied only to the analog circuit after being transferred via the common test infrastructure and the test interface of the analog circuit. This HT attack cannot be detected or prevented in the analog domain and it exploits the dense digital circuit to hide effectively its footprint.

The deployment of Artificial Intelligence (AI) hardware accelerators in a variety of applications, including safety-critical ones, requires assessing their inherent reliability to hardware-level faults and developing cost-effective fault tolerance techniques. This entails performing large-scale fault simulation experiments. However, transistor-level fault simulation is prohibitive and fault simulation should be carried out at a higher abstraction level. In this work, we focus on spiking neural networks (SNNs), and we follow a bottom-up approach starting from transistor-level simulations for developing a neuron behavioral-level fault model that can be readily employed for performing behavioral-level fault simulation of deep SNNs.