18 research outputs found

    Investigation into Photon Emissions as a Side-Channel Leakage in Two Microcontrollers: A Focus on SRAM Blocks

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    Microcontrollers are extensively utilized across a diverse range of applications. However, with the escalating usage of these devices, the risk to their security and the valuable data they process correspondingly intensifies. These devices could potentially be susceptible to various security threats, with side channel leakage standing out as a notable concern. Among the numerous types of side-channel leakages, photon emissions from active devices emerge as a potentially significant concern. These emissions, a characteristic of all semiconductor devices including microcontrollers, occur during their operation. Depending on the operating point and the internal state of the chip, these emissions can reflect the device’s internal operations. Therefore, a malicious individual could potentially exploit these emissions to gain insights into the computations being performed within the device. This dissertation delves into the investigation of photon emissions from the SRAM blocks of two distinct microcontrollers, utilizing a cost-effective setup. The aim is to extract information from these emissions, analyzing them as potential side-channel leakage points. In the first segment of the study, a PIC microcontroller variant is investigated. The quiescent photon emissions from the SRAM are examined. A correlation attack was successfully executed on these emissions, which led to the recovery of the AES encryption key. Furthermore, differential analysis was used to examine the location of SRAM bits. The combination of this information with the application of an image processing method, namely the Structural Similarity Index (SSIM), assisted in revealing the content of SRAM cells from photon emission images. The second segment of this study, for the first time, emphasizes on a RISC-V chip, examining the photon emissions of the SRAM during continuous reading. Probing the photon emissions from the row and column detectors led to the identification of a target word location, which is capable of revealing the AES key. Also, the content of target row was retrieved through the photon emissions originating from the drivers and the SRAM cells themselves. Additionally, the SSIM technique was utilized to determine the address of a targeted word in RISC-V photon emissions which cannot be analyzed through visual inspection. The insights gained from this research contribute to a deeper understanding of side-channel leakage via photon emissions and demonstrate its potential potency in extracting critical information from digital devices. Moreover, this information significantly contributes to the development of innovative security measures, an aspect becoming increasingly crucial in our progressively digitized world

    Evaluation of Single Event Effects Using the Ultrafast Pulsed Laser Facility at the Saskatchewan Structural Sciences Centre

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    Single event effects have been an issue in microelectronic devices and circuits for some time, especially those used in radiation-intense environments such as space. Traditionally, devices have been tested using particle accelerator facilities for evaluation of the various single event effects phenomena. However, testing at these facilities can be prohibitive to many research groups due to costs and time availability. As a result, pulsed laser testing has evolved to become a standard, additional testing methodology for evaluating single event effects. Not only do pulsed laser facilities generally offer more flexibility in terms of cost, but it is also possible to gain additional information about the spatial and temporal nature of single event effect generation in sensitive areas of a device. To meet the needs of the radiation effects community, pulsed laser facilities have continued to be set up around the world. One of these includes the facility at the Saskatchewan Structural Sciences Centre. An earlier iteration of the facility previously existed which utilized a different equipment set and did not have the two photon absorption capabilities that the current version does. In this thesis, a sample of the work performed at the facility using both the single and two photon absorption capabilities are provided to demonstrate its capabilities; the devices tested for single event effect response included two Hall effect sensors and a Xilinx Virtex-5 FPGA. Additionally, a description of the main features of the facility in its current form is given. Through this work, the feasibility of the facility to provide results to users, both academic and industrial, is demonstrated

    A DETECTION AND DATA ACQUISITION SYSTEM FOR PRECISION BETA DECAY SPECTROSCOPY

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    Free neutron and nuclear beta decay spectroscopy serves as a robust laboratory for investigations of the Standard Model of Particle Physics. Observables such as decay product angular correlations and energy spectra overconstrain the Standard Model and serve as a sensitive probe for Beyond the Standard Model physics. Improved measurement of these quantities is necessary to complement the TeV scale physics being conducted at the Large Hadron Collider. The UCNB, 45Ca, and Nab experiments aim to improve upon existing measurements of free neutron decay angular correlations and set new limits in the search for exotic couplings in beta decay. To achieve these experimental goals, a highly-pixelated, thick silicon detector with a 100 nm entrance window has been developed for precision beta spectroscopy and the direct detection of 30 keV beta decay protons. The detector has been characterized for its performance in energy reconstruction and particle arrival time determination. A Monte Carlo simulation of signal formation in the silicon detector and propagation through the electronics chain has been written to develop optimal signal analysis algorithms for minimally biased energy and timing extraction. A tagged-electron timing test has been proposed and investigated as a means to assess the validity of these Monte Carlo efforts. A universal platform for data acquisition (DAQ) has been designed and implemented in National Instrument\u27s PXIe-5171R digitizer/FPGA hardware. The DAQ retains a ring buffer of the most recent 400 ms of data in all 256 channels, so that a waveform trace can be returned from any combination of pixels and resolution for complete energy reconstruction. Low-threshold triggers on individual channels were implemented in FPGA as a generic piecewise-polynomial filter for universal, real-time digital signal processing, which allows for arbitrary filter implementation on a pixel-by-pixel basis. This system is universal in the sense that it has complete flexible, complex, and debuggable triggering at both the pixel and global level without recompiling the firmware. The culmination of this work is a system capable of a 10 keV trigger threshold, 3 keV resolution, and maximum 300 ps arrival time systematic, even in the presence of large amplitude noise components

    Acta Cybernetica : Volume 21. Number 1.

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    Microscale controlled continuous cell culture

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    Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 489-500).Measurements of metabolic and cellular activity through substrate and product interactions are highly dependent on environmental conditions and cellular metabolic state. For such experiments to be feasible, continuous cultures are utilized to ensure consistent conditions. However, since medium must be replenished every cell doubling time, costs can be prohibitive in large reactors. An integrated microscale bioreactor with built-in fluid metering and environmental control will enable programmed experiments capable of generating reproducible data routinely. This work develops an instrument capable of supporting automated microscale continuous culture experiments. The instrument consists of a plastic-PDMS device capable of continuous flow reactions without volume drift. A novel bonding process is invented to fabricate devices with chemically stable interfaces against water, acids, and bases. We introduce a direct CNC machining and chemical bonding fabrication process for production of fluidic devices with a 1 mL working volume, high oxygen transfer rate (kLa ~ 0.025 s-1), fast mixing (2 s), accurate flow control (± 18 nL), and closed loop control over temperature, cell density, oxygen, and pH. Providing control over environmental parameters allows the system to perform different types of cell culture on a single device, such as batch, fed-batch, chemostat, and turbidostat continuous culture. Validation experiments demonstrate that cells can be grown to high optical densities (OD = 50) and production of commercially relevant chemicals such as DNA vaccines are comparable to large scale bench fermentations. Continuous cultures are also demonstrated without contamination for 3 weeks in a single device and both steady state and dynamically controlled conditions are possible, allowing observations of cell metabolic dynamics.by Kevin Shao-Kwan Lee.Ph.D

    Advanced Technique and Future Perspective for Next Generation Optical Fiber Communications

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    Optical fiber communication industry has gained unprecedented opportunities and achieved rapid progress in recent years. However, with the increase of data transmission volume and the enhancement of transmission demand, the optical communication field still needs to be upgraded to better meet the challenges in the future development. Artificial intelligence technology in optical communication and optical network is still in its infancy, but the existing achievements show great application potential. In the future, with the further development of artificial intelligence technology, AI algorithms combining channel characteristics and physical properties will shine in optical communication. This reprint introduces some recent advances in optical fiber communication and optical network, and provides alternative directions for the development of the next generation optical fiber communication technology
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