Globalization of the integrated circuit (IC) design industry is making it easy for rogue elements in the supply chain to pirate ICs, overbuild ICs, and insert hardware Trojans. Due to supply chain attacks, the IC industry is losing approximately $4 billion annually. One way to protect ICs from these attacks is to encrypt the design by inserting additional gates such that correct outputs are produced only when specific inputs are applied to these gates. The state-of-the-art logic encryption technique inserts gates randomly into the design, but does not necessarily ensure that wrong keys corrupt the outputs. Our technique ensures that wrong keys corrupt the outputs. We relate logic encryption to fault propagation analysis in IC testing and develop a fault analysis-based logic encryption technique. This technique enables a designer to controllably corrupt the outputs. Specifically, to maximize the ambiguity for an attacker, this technique targets 50% Hamming distance between the correct and wrong outputs (ideal case) when a wrong key is applied. Furthermore, this 50% Hamming distance target is achieved using a smaller number of additional gates when compared to random logic encryption.
10 January 2014 in IEEE Transactions on Neural Networks and Learning Systems
By mimicking the highly parallel biological systems, neuromorphic hardware provides the capability of information processing within a compact and energy-efficient platform. However, traditional Von Neumann architecture and the limited signal connections have severely constrained the scalability and performance of such hardware implementations. Recently, many research efforts have been investigated in utilizing the latest discovered memristors in neuromorphic systems due to the similarity of memristors to biological synapses. In this paper, we explore the potential of a memristor crossbar array that functions as an autoassociative memory and apply it to brain-state-in-a-box (BSB) neural networks. Especially, the recall and training functions of a multianswer character recognition process based on the BSB model are studied. The robustness of the BSB circuit is analyzed and evaluated based on extensive Monte Carlo simulations, considering input defects, process variations, and electrical fluctuations. The results show that the hardware-based training scheme proposed in the paper can alleviate and even cancel out the majority of the noise issue.
Multiple neuromorphic systems use spiking neural networks (SNNs) to perform computation in a way that is inspired by concepts learned about the human brain. SNNs are artificial networks made up of neurons that fire a pulse, or spike, once the accumulated value of the inputs to the neuron exceeds a threshold. One of the most challenging parts of designing neuromorphic hardware is handling the vast degree of connectivity that neurons have with each other in the form of synaptic connections. This paper analyzes the neuromorphic systems Neurogrid, Braindrop, SpiNNaker, BrainScaleS, TrueNorth, Loihi, Darwin, and Dynap-SEL; and discusses the design of large scale spiking communication networks used in such systems. In particular, this paper looks at how each of these systems solved the challenges of forming packets with spiking information and how these packets are routed within the system. The routing of packets is analyzed at two scales: How the packets should be routed when traveling a short distance, and how the packets should be routed over longer global connections. Additional topics, such as the use of asynchronous circuits, robustness in communication, connection with a host machine, and network synchronization are also covered.
Information security has emerged as an important system and application metric. Classical security solutions use algorithmic mechanisms that address a small subset of emerging security requirements, often at high-energy and performance overhead. Further, emerging side-channel and physical attacks can compromise classical security solutions. Hardware security solutions overcome many of these limitations with less energy and performance overhead. Nanoelectronics-based hardware security preserves these advantages while enabling conceptually new security primitives and applications. This tutorial paper shows how one can develop hardware security primitives by exploiting the unique characteristics such as complex device and system models, bidirectional operation, and nonvolatility of emerging nanoelectronic devices. This paper then explains the security capabilities of several emerging nanoelectronic devices: memristors, resistive random-access memory, contact-resistive random-access memory, phase change memories, spin torque-transfer random-access memory, orthogonal spin transfer random access memory, graphene, carbon nanotubes, silicon nanowire field-effect transistors, and nanoelectronic mechanical switches. Further, the paper describes hardware security primitives for authentication, key generation, data encryption, device identification, digital forensics, tamper detection, and thwarting reverse engineering. Finally, the paper summarizes the outstanding challenges in using emerging nanoelectronic devices for security.