The low area probing detector as a countermeasure against invasive attacks

© 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksMicroprobing allows intercepting data from on-chip wires as well as injecting faults into data or control lines. This makes it a commonly used attack technique against security-related semiconductors, such as smart card controllers. We present the low area probing detector (LAPD) as an efficient approach to detect microprobing. It compares delay differences between symmetric lines such as bus lines to detect timing asymmetries introduced by the capacitive load of a probe. Compared with state-of-the-art microprobing countermeasures from industry, such as shields or bus encryption, the area overhead is minimal and no delays are introduced; in contrast to probing detection schemes from academia, such as the probe attempt detector, no analog circuitry is needed. We show the Monte Carlo simulation results of mismatch variations as well as process, voltage, and temperature corners on a 65-nm technology and present a simple reliability optimization. Eventually, we show that the detection of state-of-the-art commercial microprobes is possible even under extreme conditions and the margin with respect to false positives is sufficient.Peer ReviewedPostprint (author's final draft

Quantum Electronics

Contains reports on eleven research projects.Air Force Rome Air Development Center (in collaboration with C.C. Leiby Jr)U.S. Air Force - Rome Air Development Center (Contract F19628-80-C-0077)National Science Foundation (Grant PHY79-09739)Joint Services Electronics Program (Contract DAAG29-80-C-0104)Air Force Geophysics Laboratory (Contract F 19628-79-C-0082)National Science Foundation (Grant DAR80-08752)National Science Foundation (Grant ECS79-19475)National Science Foundation (Grant ECS80-17705)National Science Foundation (Grant ENG79-09980

Development of a portable time-domain system for diffuse optical tomography of the newborn infant brain

Conditions such as hypoxic-ischaemic encephalopathy (HIE) and perinatal arterial ischaemic stroke (PAIS) are causes of lifelong neurodisability in a few hundred infants born in the UK each year. Early diagnosis and treatment are key, but no effective bedside detection and monitoring technology is available. Non-invasive, near-infrared techniques have been explored for several decades, but progress has been inhibited by the lack of a portable technology, and intensity measurements, which are strongly sensitive to uncertain and variable coupling of light sources and detector to the scalp. A technique known as time domain diffuse optical tomography (TD-DOT) uses measurements of photon flight times between sources and detectors placed on the scalp. Mean flight time is largely insensitive to the coupling and variation in mean flight time can reveal spatial variation in blood volume and oxygenation in regions of brain sampled by the measurements. While the cost, size and high power consumption of such technology have hitherto prevented development of a portable imaging system, recent advances in silicon technology are enabling portable and low-power TD-DOT devices to be built. A prototype TD-DOT system is proposed and demonstrated, with the long-term aim to design a portable system based on independent modules, each supporting a time-of-flight detector and a pulsed source. The operation is demonstrated of components that can be integrated in a portable system: silicon photodetectors, integrated circuit-based signal conditioning and time detection -- built using a combination of off-the-shelf components and reconfigurable hardware, standard computer interfaces, and data acquisition and calibration software. The only external elements are a PC and a pulsed laser source. This thesis describes the design process, and results are reported on the performance of a 2-channel system with online histogram generation, used for phantom imaging. Possible future development of the hardware is also discussed

Quantum Cryptography

Quantum cryptography could well be the first application of quantum mechanics at the individual quanta level. The very fast progress in both theory and experiments over the recent years are reviewed, with emphasis on open questions and technological issues.Comment: 55 pages, 32 figures; to appear in Reviews of Modern Physic

Synergistic information supports modality integration and flexible learning in neural networks solving multiple tasks

Striking progress has been made in understanding cognition by analyzing how the brain is engaged in different modes of information processing. For instance, so-called synergistic information (information encoded by a set of neurons but not by any subset) plays a key role in areas of the human brain linked with complex cognition. However, two questions remain unanswered: (a) how and why a cognitive system can become highly synergistic; and (b) how informational states map onto artificial neural networks in various learning modes. Here we employ an information-decomposition framework to investigate neural networks performing cognitive tasks. Our results show that synergy increases as networks learn multiple diverse tasks, and that in tasks requiring integration of multiple sources, performance critically relies on synergistic neurons. Overall, our results suggest that synergy is used to combine information from multiple modalities—and more generally for flexible and efficient learning. These findings reveal new ways of investigating how and why learning systems employ specific information-processing strategies, and support the principle that the capacity for general-purpose learning critically relies on the system’s information dynamics

Novel linear and nonlinear optical signal processing for ultra-high bandwidth communications

The thesis is articulated around the theme of ultra-wide bandwidth single channel signals. It focuses on the two main topics of transmission and processing of information by techniques compatible with high baudrates. The processing schemes introduced combine new linear and nonlinear optical platforms such as Fourier-domain programmable optical processors and chalcogenide chip waveguides, as well as the concept of neural network. Transmission of data is considered in the context of medium distance links of Optical Time Division Multiplexed (OTDM) data subject to environmental fluctuations. We experimentally demonstrate simultaneous compensation of differential group delay and multiple orders of dispersion at symbol rates of 640 Gbaud and 1.28 Tbaud. Signal processing at high bandwidth is envisaged both in the case of elementary post-transmission analog error mitigation and in the broader field of optical computing for high level operations (“optical processor”). A key innovation is the introduction of a novel four-wave mixing scheme implementing a dot-product operation between wavelength multiplexed channels. In particular, it is demonstrated for low-latency hash-key based all-optical error detection in links encoded with advanced modulation formats. Finally, the work presents groundbreaking concepts for compact implementation of an optical neural network as a programmable multi-purpose processor. The experimental architecture can implement neural networks with several nodes on a single optical nonlinear transfer function implementing functions such as analog-to-digital conversion. The particularity of the thesis is the new approaches to optical signal processing that potentially enable high level operations using simple optical hardware and limited cascading of components

Développement de circuits logiques programmables résistants aux alas logiques en technologie CMOS submicrométrique

The electronics associated to the particle detectors of the Large Hadron Collider (LHC), under construction at CERN, will operate in a very harsh radiation environment. Most of the microelectronics components developed for the first generation of LHC experiments have been designed with very precise experiment-specific goals and are hardly adaptable to other applications. Commercial Off-The-Shelf (COTS) components cannot be used in the vicinity of particle collision due to their poor radiation tolerance. This thesis is a contribution to the effort to cover the need for radiation-tolerant SEU-robust programmable components for application in High Energy Physics (HEP) experiments. Two components are under development: a Programmable Logic Device (PLD) and a Field-Programmable Gate Array (FPGA). The PLD is a fuse-based, 10-input, 8-I/O general architecture device in 0.25 micron CMOS technology. The FPGA under development is instead a 32x32 logic block array, equivalent to ~25k gates, in 0.13 micron CMOS. This work focussed also on the research for an SEU-robust register in both the mentioned technologies. The SEU-robust register is employed as a user data flip-flop in the FPGA and PLD designs and as a configuration cell as well in the FPGA design

High data rate optical transceiver terminal

The objectives of this study were: (1) to design a 400 Mbps optical transceiver terminal to operate from a high-altitude balloon-borne platform in order to permit the quantitative evaluation of a space-qualifiable optical communications system design, (2) to design an atmospheric propagation experiment to operate in conjunction with the terminal to measure the degrading effects of the atmosphere on the links, and (3) to design typical optical communications experiments for space-borne laboratories in the 1980-1990 time frame. As a result of the study, a transceiver package has been configured for demonstration flights during late 1974. The transceiver contains a 400 Mbps transmitter, a 400 Mbps receiver, and acquisition and tracking receivers. The transmitter is a Nd:YAG, 200 Mhz, mode-locked, CW, diode-pumped laser operating at 1.06 um requiring 50 mW for 6 db margin. It will be designed to implement Pulse Quaternary Modulation (PQM). The 400 Mbps receiver utilizes a Dynamic Crossed-Field Photomultiplier (DCFP) detector. The acquisition receiver is a Quadrant Photomultiplier Tube (QPMT) and receives a 400 Mbps signal chopped at 0.1 Mhz