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Design and FPGA Implementation of pre-computation Based Radix-4 Hyperbolic CORDIC for Direct Digital Synthesis

JOURNAL OF SIGNAL PROCESSING SYSTEMS FOR SIGNAL IMAGE AND VIDEO TECHNOLOGY 2023年第6期95卷 765-775页

作者： Pujari, Shubhanjay S. S. Bhaskar, M. Natl Inst Technol Dept Elect & Commun Engn Tiruchirappalli India

This paper presents the hardware and delay efficient design of a radix-4 pipelined hyperbolic Coordinate Rotation Digital Computer (CORDIC) architecture. The proposed design uses pre-computation based micro-rotation sequence generation to reduce the cycle time and number of iterations. It also eliminates the need for residue angle computation in every iteration that helps to enhance the operating speed. The methodology finds a linear relation between rotation angle input and micro-rotation sequence by selectively choosing elementary angles from the set of valid angles. Therefore, it requires six clock cycles to compute the hyperbolic functions (cosh/sinh). Further, the region of convergence (ROC) of the proposed design is extended to cover the entire coordinate space. Based on the proposed hyperbolic CORDIC design, a hyperbolic (Direct Digital Synthesis) DDS is implemented using XC7VX330T (Vertex-7 family) field-programmable gate array (FPGA) in Xilinx ISE platform. The proposed design achieves 47% and 37% savings in basic logic elements and number of slices respectively than recent designs. The design also achieves an improved slice delay product of 5.28 and a maximum frequency of operation of 500.75 MHz.

关键词： pre-computation Hyperbolic CORDIC Radix-4 DDS

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DAI: How pre-computation Speeds up Data Analysis 24th

DAI: How Pre-computation Speeds up Data Analysis

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24th International Conference on computational Science (ICCS)

作者： Duwe, Kira Kuhn, Michael Ecole Polytech Fed Lausanne Lausanne Switzerland Otto von Guericke Univ Magdeburg Germany

ISBN: (纸本)9783031637537;9783031637513

As data sizes continue to expand, the challenge of conducting meaningful analysis grows. Utilizing I/O (Input/Output) libraries, such as HDF5 (Hierarchical Data Format) and ADIOS2 (Adaptable IO System), facilitates the filtering of raw data, with prior research highlighting the advantages of dissecting these formats for enhanced metadata management. Our study introduces a novel data management technique aimed at boosting query performance for HPC analysis applications through the automatic precomputation of commonly used data characteristics, as identified by our user survey. The Data Analysis Interface (DAI), developed for the JULEA storage framework, not only enables querying this enriched metadata but also shows how domain-specific features can be integrated, demonstrating a potential improvement in query times by up to 22,000 times.

关键词： Scientific data management Self-describing data formats HPC applications pre-computation

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pre-computation Scheme of Window τNAF for Koblitz Curves Revisited 40th

Pre-computation Scheme of Window τNAF for Koblitz Curves Re...

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40th Annual International Conference on the Theory and Applications of Cryptographic Techniques (EUROCRYPT)

作者： Yu, Wei Xu, Guangwu Chinese Acad Sci Inst Informat Engn State Key Lab Informat Secur Beijing 100093 Peoples R China Minist Educ Key Lab Cryptol Technol & Informat Secur Qingdao 266237 Shandong Peoples R China Shandong Univ Sch Cyber Sci & Technol Qingdao 266237 Shandong Peoples R China

ISBN: (纸本)9783030778866;9783030778859

Let E-a/F-2 : y(2) + xy = x(3) + ax(2) + 1 be a Koblitz curve. The window tau-adic non-adjacent form (window tau NAF) is currently the standard representation system to perform scalar multiplications on E-a/F-2m utilizing the Frobenius map tau. This work focuses on the pre-computation part of scalar multiplication. We first introduce mu(tau) over bar -operations where mu = (-1)(1-a) and (tau) over bar is the complex conjugate of tau. Efficient formulas of mu(tau) over bar -operations are then derived and used in a novel pre-computation scheme. Our pre-computation scheme requires 6M+ 6S, 18M+ 17S, 44M+ 32S, and 88M+ 62S (a = 0) and 6M+ 6S, 19M+ 17S, 46M+ 32S, and 90M+ 62S (a = 1) for window tau NAF with widths from 4 to 7 respectively. It is about two times faster, compared to the state-of-the-art technique of pre-computation in the literature. The impact of our new efficient pre-computation is also reflected by the significant improvement of scalar multiplication. Traditionally, window tau NAF with width at most 6 is used to achieve the best scalar multiplication. Because of the dramatic cost reduction of the proposed pre-computation, we are able to increase the width for window tau NAF to 7 for a better scalar multiplication. This indicates that the pre-computation part becomes more important in performing scalar multiplication. With our efficient pre-computation and the new window width, our scalar multiplication runs in at least 85.2% the time of Kohel's work (Eurocrypt'2017) combining the best previous pre-computation. Our results push the scalar multiplication of Koblitz curves, a very well-studied and long-standing research area, to a significant new stage.

关键词： Elliptic curve cryptography Koblitz curve Scalar multiplication Window tNAF pre-computation

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Boosting Graph Similarity Search through pre-computation 21

Boosting Graph Similarity Search through Pre-Computation

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ACM SIGMOD International Conference on Management of Data (SIGMOD)

作者： Kim, Jongik Jeonbuk Natl Univ Jeonju South Korea

ISBN: (纸本)9781450383431

Graph similarity search is to retrieve all graphs from a graph database whose graph edit distance (GED) to a query graph is within a given threshold. As GED computation is NP-hard, existing solutions adopt the filtering-and-verification framework, where the main focus is on the filtering phase to reduce the number of GED verifications. However, existing filtering techniques have inherently limited filtering capabilities, and suffer from a large number of GED verifications. To address the problem, in this paper, we propose a fundamentally different approach that utilizes pre-computed GEDs between data graphs in the filtering phase. Based on the approach, we develop a novel search framework Nass, which substantially reduces the verification workload. Because the efficiency of GED computation is essential in GED pre-computation, not to mention the verification of candidate graphs, we also propose an efficient GED computation algorithm as a part of Nass. We conduct extensive experiments on real datasets, and show Nass significantly outperforms the state-of-the art solutions.

关键词： graph similarity search graph edit distance pre-computation

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On the Optimal pre-computation of Window τNAF for Koblitz Curves

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IEEE TRANSACTIONS ON COMPUTERS 2016年第9期65卷 2918-2924页

作者： Trost, William R. Xu, Guangwu Univ Wisconsin Dept EE & CS Milwaukee WI 53211 USA

Koblitz curves have been an important subject of consideration for both theoretical andpractical interests. The window tau-adic algorithm of Solinas (window tau NAF) is the most powerful method for computing point multiplication for Koblitz curves. pre-computation plays an important role in improving the performance of point multiplication. In this paper, the concept of optimal pre-computation for window tau NAF is formulated. In this setting, an optimal pre-computation has some mathematically natural and clean forms, and requires 2(w-2) - 1 point additions and two evaluations of the Frobenius map tau, where w is the window width. One of the main results of this paper is to construct an optimal pre-computation scheme for each window width w from 4 to 15 (more than practical needs). These pre-computations can be easily incorporated into implementations of window tau NAF. The ideas in the paper can also be used to construct other suitable pre-computations. This paper includes a discussion of coefficient sets for window tau NAF and the divisibility by powers of tau through different approaches. Some issues of implementation are also discussed.

关键词： Elliptic curve cryptography window tau-non adjacent form pre-computation

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A Novel Window τNAF on Koblitz Curves 29th

A Novel Window τNAF on Koblitz Curves

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29th Australasian Conference on Information Security and Privacy (ACISP)

作者： Li, Xiuxiu Yu, Wei Wang, Kunpeng Chinese Acad Sci Inst Informat Engn Key Lab Cyberspace Secur Def Beijing 100085 Peoples R China State Key Lab Cryptol POB 5159 Beijing 100878 Peoples R China Univ Chinese Acad Sci Sch Cyberspace Secur Beijing Peoples R China

ISBN: (纸本)9789819750245;9789819750252

The window tau-adic non-adjacent form (window tau NAF) was initially proposed by Solinas in 2000 as a method to calculate scalar multiplication on the Koblitz curves. To ensure the correctness of the window tau NAF, Blake, Murty, and Xu demonstrated that the pre-computation scheme of this method must be convergent. To date, the standard representation system for scalar multiplication on the Koblitz curve E-a/F-2m using the Frobenius map tau remains the window tau NAF. In this paper, we present a novel algorithm that extends the window tau NAF approach and improves its pre-computation scheme. Our algorithm integrates several window tau NAF, where the initial few are non-convergent and the final one is the standard window tau NAF. Compared with the previous state-of-the-art method, our approach achieves a 5% reduction in the time for implementing scalar multiplication when using the mu 4-Koblitz curves and LD coordinates. This work offers significant advancements in optimizing scalar multiplication on Koblitz curves.

关键词： Elliptic curve cryptography Koblitz curve Scalar multiplication Window tNAF pre-computation

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Instantaneous Whole-brain pressure Estimation in Translational Head Impact via pre-computation

Instantaneous Whole-brain Pressure Estimation in Translation...

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The 12th International Forum of Automotive Traffic Safety

作者： Wei ZHAO Songbai JI Thayer School of Engineering Dartmouth College Department of Surgery and of Orthopaedic Surgery Geisel School of MedicineDartmouth College

Background:Finite element models are effective tools to study brain injury in automotive crashes due to their unique capability in providing tissue-level responses that is otherwise infeasible in a crash ***,achieving an optimal tradeoff between model sophistication and computational efficiency is a practical ***:In this study,we intend to propose a pre-computation scheme and present a simple,yet effective technique to instantly estimate whole-brain pressures induced by linear ***:Three hydrostatic atlas pressure responses along the three major axes of the head were ***-brain pressures were then superimposed in real-time for an arbitrary translational head *** accuracy of the pressure estimation scheme was tested in seven real-world impact cases ranging from cadaveric experiments to reconstructed automotive ***:This study successfully employed a simple and effective pre-computation strategy to estimate whole-brain pressures in real-time for translational head impacts（<0.1 sec on a lap-top vs.5 minutes for the overall processing on a high-end workstation）.The technique was efficient and sufficiently accurate for most cases as long as the impulse duration is greater than 2 ms,demonstrating its high effectiveness for real-world ***:This technique may have the potential to aid kinematics-based injury metrics such as head injury criterion（HIC）to more effectively assess the risk and severity of pressure-induced coup/countercoup or moderate to severe brain injuries in the future.

关键词： Traumatic brain injury translational head impact linear acceleration pre-computation Dartmouth Head Injury Mode

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On Time-Space Lower Bounds for Finding Short Collisions in Sponge Hash Functions 1

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21st International Conference on Theory of Cryptography (TCC)

作者： Akshima Duan, Xiaoqi Guo, Siyao Liu, Qipeng NYU Shanghai Shanghai Frontiers Sci Ctr Artificial Intelligenc Shanghai Peoples R China Swiss Fed Inst Technol Zurich Switzerland Univ Calif San Diego San Diego CA USA

ISBN: (数字)9783031486210

ISBN: (纸本)9783031486203;9783031486210

Sponge paradigm, used in the design of SHA-3, is an alternative hashing technique to the popular Merkle-Damgard paradigm. We revisit the problem of finding B-block-long collisions in sponge hash functions in the auxiliary-input random permutation model, in which an attacker gets a piece of S-bit advice about the random permutation and makes T (forward or inverse) oracle queries to the random permutation. Recently, significant progress has been made in the Merkle-Damgard setting and optimal bounds are known for a large range of parameters, including all constant values of B. However, the sponge setting is widely open: there exist significant gaps between known attacks and security bounds even for B = 1. Freitag, Ghoshal and Komargodski (CRYPTO 2022) showed a novel attack for B = 1 that takes advantage of the inverse queries and achieves advantage (Omega) over tilde (min((ST2)-T-2 /2(2c), ((ST)-T-2/2(2c))(2/3))+ T-2 /2(r)), where r is bit-rate and c is the capacity of the random permutation. However, they only showed an (O) over tilde (ST/2(c) + T-2 /2(r)) security bound, leaving open an intriguing quadratic gap. For B = 2, they beat the general security bound by Coretti, Dodis, Guo (CRYPTO 2018) for arbitrary values of B. However, their highly non-trivial argument is quite laborious, and no better (than the general) bounds are known for B >= 3. In this work, we study the possibility of proving better security bounds in the sponge setting. To this end, - For B = 1, we prove an improved (O) over tilde ((ST2)-T-2/2(2c) + S/2(c) + T/2(c) +T-2/2(r)) bound. Our bound strictly improves the bound by Freitag et al., and is optimal for ST2 <= 2(c). - For B = 2, we give a considerably simpler and more modular proof, recovering the bound obtained by Freitag et al. - We obtain our bounds by adapting the recent multi-instance technique of Akshima, Guo and Liu (CRYPTO 2022) which bypasses the limitations of prior techniques in the Merkle-Damgard setting. To complement our results,

关键词： Collision hash functions Sponge multi-instance pre-computation auxiliary input

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Direct point-cloud-based numerical analysis using octree meshes

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COMPUTERS & STRUCTURES 2023年 289卷

作者： Zhang, Junqi Eisentraeger, Sascha Zhan, Yifan Saputra, Albert Song, Chongmin Beijing Univ Technol Key Lab Urban Secur & Disaster Engn Minist Educ Beijing 100124 Peoples R China Otto Guericke Univ Magdeburg Inst Mech Chair Computat Mech D-39106 Magdeburg Saxony Anhalt Germany Univ New South Wales Sch Civil & Environm Engn Sydney NSW 2052 Australia

Point-cloud-based geometry acquisition techniques have seen an increased deployment in recent years and can be used in many branches of science and engineering. Different from conventional computer aided design (CAD) models, point-cloud data can be directly obtained by applying surveying technology, such as laser scanning devices. This opens a pathway to an efficient and highly automatic acquisition of the geometric model. However, in order to perform numerical analysis on point-cloud models using conventional finite element approaches, a surface reconstruction is required, which is both time consuming and error-prone. Therefore, a direct numerical analysis framework based on point-cloud data in conjunction with polyhedral element techniques is developed in this contribution. To this end, a robust and efficient meshing paradigm based on the direct use of point-cloud data (without surface reconstruction) is proposed. From the geometric model, a trimmed octree mesh containing only a limited number of master elements (element patterns) is directly generated, which is highly suitable for pre-computation techniques and parallelization (high-performance computing-HPC). By computing the element stiffness and mass matrices from pre-computed master elements via scaling, a fully automatic HPC framework is developed. By means of six numerical examples, we demonstrate the robustness, versatility, and efficiency of the developed methodology in handling (geometrically) complex engineering problems.

关键词： Point-cloud pre-computation Trimmed octree mesh Polyhedral elements Scaled boundary finite element method

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Branch Runahead: An Alternative to Branch prediction for Impossible to predict Branches 21

Branch Runahead: An Alternative to Branch Prediction for Imp...

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54th Annual IEEE/ACM International Symposium on Microarchitecture (MICRO)

作者： Pruett, Stephen Patt, Yale N. Univ Texas Austin Austin TX 78712 USA

ISBN: (纸本)9781450385572

High performance microprocessors require high levels of instruction supply. Branch prediction has been the most important driver of this for nearly 30 years. Unfortunately, modern predictors are increasingly bottlenecked by hard-to-predict data-dependent branches that fundamentally cannot be predicted via a history based approach. pre-computation of branch instructions has been suggested as a solution, but such schemes require a careful trade-off between timeliness and complexity. This paper introduces Branch Runahead: a low-cost, hardware-only solution that achieves high accuracy while only performing lightweight pre-computation. The result: a reduction in branch MPKI of 47.5% and an average improvement in IPC of 16.9%.

关键词： Branch prediction pre-computation Control Independence

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