76 research outputs found

    What We Can Expect from Consumer-Driven Health Care

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    Type: Commentar

    Compact Implementations of LEA Block Cipher for Low-End Microprocessors

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    In WISA\u2713, a novel lightweight block cipher named LEA was released. This algorithm has certain useful features for hardware and software implementations, i.e., simple ARX operations, non-S-box architecture, and 32-bit word size. These features are realized in several platforms for practical usage with high performance and low overheads. In this paper, we further improve 128-, 192- and 256-bit LEA encryption for low-end embedded processors. Firstly we present speed optimization methods. The methods split a 32-bit word operation into four byte-wise operations and avoid several rotation operations by taking advantages of efficient byte-wise rotations. Secondly we reduce the code size to ensure minimum code size.We nd the minimum inner loops and optimize them in an instruction set level. After then we construct the whole algorithm in a partly unrolled fashion with reasonable speed. Finally, we achieved the fastest LEA implementations, which improves performance by 10.9% than previous best known results. For size optimization, our implemen- tation only occupies the 280B to conduct LEA encryption. After scaling, our implementation achieved the smallest ARX implementations so far, compared with other state-of-art ARX block ciphers such as SPECK and SIMON

    Uptake and Utilization of the COVID-19 Alert App within a University Community in New York

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    The rapid onset of the COVID-19 pandemic elicited a swift response to control the virus ubiquitous within the United States. Expanded telehealth and health informatics became critical components of the pandemic response. The aim of this study was to assess the utilization of the COVID-19 New York (NY) Alert App and identify the perceived benefits and limitations of the App. A cross-sectional design was employed to collect data by using questionnaires with closed-ended questions. The survey was developed and administered during March through April 2021. The study found that the highest rated benefit from using the COVID-19 NY Alert App was receiving alerts about being in close proximity to individuals diagnosed with COVID-19. Results showed that ineffective (insufficient and inappropriate) usage was the highest rated potential challenge for using the App. Study subjects were likely to download this Alert App when they perceived more benefits and less barriers to using the App. Findings from this study can help improve utilization of the App and inform development of similar tele-education tools. The study illuminated considerations for health information applications in scaling-up traditional COVID-19 tracing efforts and may facilitate the design of similar emergency preparedness health technology.

    Secure Binary Field Multiplication

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    Binary eld multiplication is the most fundamental building block of binary eld Elliptic Curve Cryptography (ECC) and Galois/Counter Mode (GCM). Both bit-wise scanning and Look-Up Table (LUT) based methods are commonly used for binary eld multiplication. In terms of Side Channel Attack (SCA), bit-wise scanning exploits insecure branch operations which leaks information in a form of timing and power consumption. On the other hands, LUT based method is regarded as a relatively secure approach because LUT access can be conducted in a regular and atomic form. This ensures a constant time solution as well. In this paper, we conduct the SCA on the LUT based binary eld multiplication. The attack exploits the horizontal Correlation Power Analysis (CPA) on weights of LUT. We identify the operand with only a power trace of binary eld multiplication. In order to prevent SCA, we also suggest a mask based binary eld multiplication which ensures a regular and constant time solution without LUT and branch statements

    Understanding the formation of the metastable ferroelectric phase in hafnia–zirconia solid solution thin films

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    Hf₁₋ₓZrₓO₂ (x ∼ 0.5–0.7) has been the leading candidate of ferroelectric materials with a fluorite crystal structure showing highly promising compatibility with complementary metal oxide semiconductor devices. Despite the notable improvement in device performance and processing techniques, the origin of its ferroelectric crystalline phase (space group: Pca2₁) formation has not been clearly elucidated. Several recent experimental and theoretical studies evidently showed that the interface and grain boundary energies of the higher symmetry phases (orthorhombic and tetragonal) contribute to the stabilization of the metastable non-centrosymmetric orthorhombic phase or tetragonal phase. However, there was a clear quantitative discrepancy between the theoretical expectation and experiment results, suggesting that the thermodynamic model may not provide the full explanation. This work, therefore, focuses on the phase transition kinetics during the cooling step after the crystallization annealing. It was found that the large activation barrier for the transition from the tetragonal/orthorhombic to the monoclinic phase, which is the stable phase at room temperature, suppresses the phase transition, and thus, plays a critical role in the emergence of ferroelectricity

    A Comparative Study on the Ferroelectric Performances in Atomic Layer Deposited Hf0.5Zr0.5O2 Thin Films Using Tetrakis(ethylmethylamino) and Tetrakis(dimethylamino) Precursors

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    Abstract The chemical, physical, and electrical properties of the atomic layer deposited Hf0.5Zr0.5O2 thin films using tetrakis(ethylmethylamino) (TEMA) and tetrakis(dimethylamino) (TDMA) precursors are compared. The ligand of the metal-organic precursors strongly affects the residual C concentration, grain size, and the resulting ferroelectric properties. Depositing Hf0.5Zr0.5O2 films with the TDMA precursors results in lower C concentration and slightly larger grain size. These findings are beneficial to grow more ferroelectric-phase-dominant film, which mitigates its wake-up effect. From the wake-up test of the TDMA-Hf0.5Zr0.5O2 film with a 2.8 MV/cm cycling field, the adverse wake-up effect was well suppressed up to 105 cycles, with a reasonably high double remanent polarization value of ~40 μC/cm2. The film also showed reliable switching up to 109 cycles with the 2.5MV/cm cycling field without involving the wake-up effect but with the typical fatigue behavior
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