scholarly journals Estimation during Design Phases of Suitable SRAM Cells for PUF Applications Using Separatrix and Mismatch Metrics

Electronics ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1479
Author(s):  
Abdel Alheyasat ◽  
Gabriel Torrens ◽  
Sebastià A. Bota ◽  
Bartomeu Alorda

Physically unclonable functions (PUFs) are used as low-cost cryptographic primitives in device authentication and secret key creation. SRAM-PUFs are well-known as entropy sources; nevertheless, due of non-deterministic noise environment during the power-up process, they are subject to low challenge-response repeatability. The dependability of SRAM-PUFs is usually accomplished by combining complex error correcting codes (ECCs) with fuzzy extractor structures resulting in an increase in power consumption, area, cost, and design complexity. In this study, we established effective metrics on the basis of the separatrix concept and cell mismatch to estimate the percentage of cells that, due to the effect of variability, will tend to the same initial state during power-up. The effects of noise and temperature in cell start-up processes were used to validate the proposed metrics. The presented metrics may be applied at the SRAM-PUF design phases to investigate the impact of different design parameters on the percentage of reliable cells for PUF applications.

2012 ◽  
Vol 2 (1) ◽  
Author(s):  
Jifeng Wang ◽  
Jorge Olortegui-Yume ◽  
Norbert Müller

AbstractA low cost, light weight, high performance composite material turbomachinery impeller with a uniquely designed blade patterns is analyzed. Such impellers can economically enable refrigeration plants to use water as a refrigerant (R718). A strength and dynamic characteristics analyses procedure is developed to assess the maximum stresses and natural frequencies of these wound composite axial impellers under operating loading conditions. Numerical simulation using FEM for two-dimensional and three-dimensional impellers was investigated. A commercially available software ANSYS is used for the finite element calculations. Analysis is done for different blade geometries and then suggestions are made for optimum design parameters. In order to avoid operating at resonance, which can make impellers suffer a significant reduction in the design life, the designer must calculate the natural frequency and modal shape of the impeller to analyze the dynamic characteristics. The results show that using composite Kevlar fiber/epoxy matrix enables the impeller to run at high tip speed and withstand the stresses, no critical speed will be matched during start-up and shut-down, and that mass imbalances of the impeller shall not pose a critical problem.


Author(s):  
Clifford H. Watson ◽  
Jane Yan ◽  
Stephen Stanfill ◽  
Liza Valentin-Blasini ◽  
Roberto Bravo Cardenas ◽  
...  

Standard machine smoking protocols provide useful information for examining the impact of design parameters, such as filter ventilation, on mainstream smoke delivery. Unfortunately, their results do not accurately reflect human smoke exposure. Clinical research and topography devices in human studies yield insights into how products are used, but a clinical setting or smoking a cigarette attached to such a device may alter smoking behavior. To better understand smokers’ use of filtered cigarette products in a more natural environment, we developed a low-cost, high-throughput approach to estimate mainstream cigarette smoke exposure on a per-cigarette basis. This approach uses an inexpensive flatbed scanner to scan smoked cigarette filter butts and custom software to analyze tar-staining patterns. Total luminosity, or optical staining density, of the scanned images provides quantitative information proportional to mainstream smoke-constituent deliveries on a cigarette-by-cigarette basis. Duplicate sample analysis using this new approach and our laboratory’s gold-standard liquid chromatography/tandem mass spectrometry (LC/MS/MS) solanesol method yielded comparable results (+7% bias) from the analysis of 20 commercial cigarettes brands (menthol and nonmentholated). The brands varied in design parameters such as length, filter ventilation, and diameter. Plots correlating the luminosity to mainstream smoked-nicotine deliveries on a per-cigarette basis for these cigarette brands were linear (average R2 > 0.91 for nicotine and R2 > 0.83 for the tobacco-specific nitrosamine NNK), on a per-brand basis, with linearity ranging from 0.15 to 3.00 mg nicotine/cigarette. Analysis of spent cigarette filters allows exposures to be characterized on a per-cigarette basis or a “daily dose” via summing across results from all filter butts collected over a 24 h period. This scanner method has a 100-fold lower initial capital cost for equipment than the LC/MS/MS solanesol method and provides high-throughput results (~200 samples per day). Thus, this new method is useful for characterizing exposure related to filtered tobacco-product use.


2014 ◽  
Vol 945-949 ◽  
pp. 35-39
Author(s):  
Shu Jing Zhao ◽  
Li Li ◽  
Fang Wang ◽  
Ji Kuang Yang

This paper aimed at investigating the injury risk and the kinematics of pedestrians in collisions with buses. A mathematical model of a production bus was developed. A parameter study of the bus-pedestrian collision was carried out by using the bus MB (multi-body model) and a validated pedestrian MB model in terms of pedestrian postures, bus front design parameters, and different impact conditions. The results indicated that the initial state of pedestrians has significant influences on their kinematic responses. The impact speed and front stiffness has remarkable effects on pedestrian injury severities. Besides, restricted bus travel speed,lowered stiffness of bus front structure and reduced ground clearance could reduce the pedestrian injury risks.


2021 ◽  
Vol 20 (2) ◽  
pp. 1-23
Author(s):  
Johanna Sepúlveda ◽  
Mathieu Gross ◽  
Andreas Zankl ◽  
Georg Sigl

System-on-Chips (SoCs) are a key enabling technology for the Internet-of-Things (IoT), a hyper-connected world where on- and inter-chip communication is ubiquitous. SoCs usually integrate cryptographic hardware cores for confidentiality and authentication services. However, these components are prone to implementation attacks. During the operation of a cryptographic core, the secret key may passively be inferred through cache observations. Access-driven attacks exploiting these observations are therefore a vital threat to SoCs operating in IoT environments. Previous works have shown the feasibility of these attacks in the SoC context. Yet, the SoC communication structure can be used to further improve access-based cache attacks. The communication attacks are not as well-understood as other micro-architectural attacks. It is important to raise the awareness of SoC designers of such a threat. To this end, we present four contributions. First, we demonstrate an improved Prime+Probe attack on four different AES-128 implementations (original transformation tables, T 0 -Only, T 2KB , and S-Box). As a novelty, this attack exploits the collisions of the bus-based SoC communication to further increase its efficiency. Second, we explore the impact of preloading on the efficiency of our communication-optimized attack. Third, we integrate three countermeasures ( shuffling , mini-tables , and Time-Division Multiple Access (TDMA) bus arbitration ) and evaluate their impact on the attack. Although shuffling and mini-tables countermeasures were proposed in previous work, their application as countermeasures against the bus-based attack was not studied before. In addition, TDMA as a countermeasure for bus-based attacks is an original contribution of this work. Fourth, we further discuss the implications of our work in the SoC design and its perspective with the new cryptographic primitives proposed in the ongoing National Institute of Standard and Technology Lightweight Cryptography competition. The results show that our improved communication-optimized attack is efficient, speeding up full key recovery by up to 400 times when compared to the traditional Prime+Probe technique. Moreover, the protection techniques are feasible and effectively mitigate the proposed improved attack.


2020 ◽  
Vol 90 (3) ◽  
pp. 30502
Author(s):  
Alessandro Fantoni ◽  
João Costa ◽  
Paulo Lourenço ◽  
Manuela Vieira

Amorphous silicon PECVD photonic integrated devices are promising candidates for low cost sensing applications. This manuscript reports a simulation analysis about the impact on the overall efficiency caused by the lithography imperfections in the deposition process. The tolerance to the fabrication defects of a photonic sensor based on surface plasmonic resonance is analysed. The simulations are performed with FDTD and BPM algorithms. The device is a plasmonic interferometer composed by an a-Si:H waveguide covered by a thin gold layer. The sensing analysis is performed by equally splitting the input light into two arms, allowing the sensor to be calibrated by its reference arm. Two different 1 × 2 power splitter configurations are presented: a directional coupler and a multimode interference splitter. The waveguide sidewall roughness is considered as the major negative effect caused by deposition imperfections. The simulation results show that plasmonic effects can be excited in the interferometric waveguide structure, allowing a sensing device with enough sensitivity to support the functioning of a bio sensor for high throughput screening. In addition, the good tolerance to the waveguide wall roughness, points out the PECVD deposition technique as reliable method for the overall sensor system to be produced in a low-cost system. The large area deposition of photonics structures, allowed by the PECVD method, can be explored to design a multiplexed system for analysis of multiple biomarkers to further increase the tolerance to fabrication defects.


Author(s):  
J.R. Caradus ◽  
D.A. Clark

The New Zealand dairy industry recognises that to remain competitive it must continue to invest in research and development. Outcomes from research have ensured year-round provision of low-cost feed from pasture while improving productivity. Some of these advances, discussed in this paper, include the use of white clover in pasture, understanding the impacts of grass endophyte, improved dairy cow nutrition, the use of alternative forage species and nitrogen fertiliser to improve productivity, demonstration of the impact of days-in-milk on profitability, and the use of feed budgeting and appropriate pasture management. Keywords: dairy, profitability, research and development


2012 ◽  
Vol 8 (1) ◽  
pp. 37-48
Author(s):  
S. Chehaibi ◽  
K. Abrougui ◽  
F. Haouala

The effects of mechanical perforation densities by extracting soil cores through an aerator Vertidrain with a working width of 1.6 m and equipped with hollow tines spaced of 65 mm, were studied on a sandy soil of a grassy sward in the Golf Course El Kantaoui in Sousse (Tunisia). The mechanical aeration was performed at two densities: 250 and 350 holes/m2. The cone penetration resistance and soil water infiltration were measured. These parameters were performed at initial state before aeration (E0) and then on the 10th, 20th and 30th day after aeration. These results showed that perforation density of 350 holes/m2 had a positive effect on the soil by reducing its cone resistance to penetration compared to the initial state (Rp = 14.8 daN/cm2). At 5 cm depth the decrease in resistance to penetration was 34% and 43% on the 10th and 20th day after aeration, respectively. However, on the 30th day after aeration the soil resistance to penetration tended to grow and its value compared to the initial state decreased only by 21 and 26%, respectively, at 5 and 15 cm of depth only by 10% and 9% with 250 holes/m2 density. The soil water infiltration made a good improvement after aeration compared to the initial state. This parameter increased from 4.8 cm/h to 8.3, 10.9 and 13.1 cm/h with 250 holes/m2 density and to 10, 12.9 and 14.8 cm/h with 350 holes/m2 density on the 10th, 20th and 30th day following the aeration.


Author(s):  
P.Venu Gopala Rao ◽  
Eslavath Raja ◽  
Ramakrishna Gandi ◽  
G. Ravi Kumar

IoT (Internet of Things) has become most significant area of research to design an efficient data enabled services with the help of sensors. In this paper, a low-cost system design for e-healthcare service to process the sensitive health data is presented. Vital signs of the human body are measured from the patient location and shared with a registered medical professional for consultation. Temperature and heart rate are the major signals obtained from a patient for the initial build of the system. Data is sent to a cloud server where processing and analysis is provided for the medical professional to analyze. Secure transmission and dissemination of data through the cloud server is provided with an authentication system and the patient could be able to track his data through a smart phone on connecting to the cloud server. A prototype of the system along with its design parameters has been discussed.


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