一种适用于多种公钥密码算法的模运算处理器

文章设计了一种能够实现多种公钥密码算法（如RSA、ECC、DSA等）的协处理器。通过分析几种常用的公钥密码算法，归纳了一组最常用的基本模运算指令。基于基本指令，设计优化了处理器硬件结构。用微代码循环调用执行这些基本指令，实现其他各种模运算指令。基于这些模运算指令，处理器可实现多种公钥密码算法的运算。该处理器支持从106位到2048位多种长度的模运算。采用流水线结构设计，处理速度较快。处理器占用芯片面积小，核心电路等效门数约为26000门，适用于智能卡等对芯片面积有严格限制的应用。     

大数模幂乘运算的VLSI实现

信息加密,数字答乐,身份证等等是信息安全领域的重要内容,只有公钥密友体制才能很好地解决这些问题,大数模幂乘运算是许多公钥密友体制的核心运算,也是运算效率提高的瓶颈。基于Ｍｏｎｔｇｏｍｅｒｙ模乘变换,构造了一种新型的脉动阵列架构模乘运算器。结合简单二进制幂运算算法,采用０．８μｍ ＣＭＯＳ工艺,成功地设计并制造了２５６ｂｉｔ模幂乘运算器ＴＨＭ２５６,电路规模为１８６７７门,芯片面积为１７．６３ｍｍ６     

一种基于CSA加法器的Montgomery模幂乘硬件实现算法

提出了一种改进的Montgomery模乘和模幂算法,该算法采用5-to-2 CSA加法器来实现Montgomery模乘算法中的超长大数加法。目前使用CSA加法器的其他模乘算法在模乘结果输出时均需要用CPA加法器来处理CSA加法器的输出结果,而本文提出的算法使得模乘运算的输入输出操作数均可采用保留进位形式,避免了进行超长操作数的CPA加法这一耗时的操作,因此显著减少了模乘运算所需时钟周期,提高了数据处理的时间效率,并加快了RSA模幂运算的速度。     

大数模幂乘算法的快速实现

大素数的选取是构造RSA密钥的关键 ,在素数的产生及测试是RSA公钥系统中的一个重要研究课题。描述了公钥密码体制中DSA、RSA等数据加密算法的原理及加密、解密过程 ,分析了各种算法的性能和适用的场合 ,针对上述算法的计算量巨大的问题 ,给出了实现数据加密较好的方法。理论和实验表明 ,该算法用于实现RSA算法 ,新算法的效率有明显的提高     

SM2高速双域 Montgomery 模乘的硬件设计

作为由国家密码管理局公布的SM2椭圆曲线公钥密码算法的核心运算,模乘的实现好坏直接决定着整个密码芯片性能的优劣．Montgomery模乘算法是目前最高效也是应用最为广泛的一种模乘算法．本文基于Mont-gomery模乘算法,设计了一种高速,且支持双域（GF（p）素数域和GF（2m ）二进制域）的Montgomery模乘器．提出了新的实现结构,以及一种新型的W allace树乘法单元．通过对模块合理的安排和复用,本设计极大的缩小了时间消耗与硬件需求,节省了大量的资源．实现256位双域模乘仅需0．34μs ．     

双有限域模乘和模逆算法及其硬件实现

有限域上的模乘和模逆运算是椭圆曲线密码体系的两个核心运算。该文在Blakley算法的基础上提出一种radix-4快速双有限域模乘算法,该算法采用Booth编码技术将原算法的迭代次数减少一半,并利用符号估计技术简化约减操作;在扩展Euclidean求逆算法的基础上提出一种能够同时支持双有限域运算的高效模逆算法,该算法不仅避免了大整数比较操作,而且提高了算法在每次迭代过程中的移位效率。然后针对这两种算法特点设计出一种能够同时完成双有限域上模乘和模逆操作的统一硬件结构。实现结果表明：256位的模乘和模逆统一硬件电路与同类型设计相比较,在电路面积没有增加的情况下,模乘运算速度提高68%,模逆运算的速度也提高了17.4%。     

一种适合流水线结构的改进FIOS模乘算法研究

SOS、CIOS、FIOS、FIPS、CIHS是Montgomery模乘算法的5个基本实现方法,其中CIOS方法一直被认为是综合最优的算法。但已经有人提出了一种改进的IFIOS算法,并用实验证明其比常用的CIOS算法有优势。首先分析了CIOS、FIOS和IFIOS实现方法,通过进位单元的重复利用和减少存储单元,提出了一种改进的IIFIOS算法。然后根据IIFIOS算法的流程,让前后两个部分并行执行,提出了适合流水线结构的改进。最后,实验结果和理论分析表明,IIFIOS软件算法有效提升了算法性能,并指出其在硬件实现上也具有一定优势。     

一种适合流水线结构的改进FIOS模乘算法研究

SOS、CIOS、FIOS、FIPS、CIHS是Montgomery模乘算法的5个基本实现方法,其中CI-OS方法一直被认为是综合最优的算法。但已经有人提出了一种改进的IFIOS算法,并用实验证明其比常用的CIOS算法有优势。首先分析了CIOS、FIOS和IFIOS实现方法,通过进位单元的重复利用和减少存储单元,提出了一种改进的IIFIOS算法。然后根据IIFIOS算法的流程,让前后两个部分并行执行,提出了适合流水线结构的改进。最后,实验结果和理论分析表明,IIFIOS软件算法有效提升了算法性能,并指出其在硬件实现上也具有一定优势。     

一种大数模幂的硬件实现设计

提出了一种实现大数模幂的硬件设计方法。其中的大数模乘部分基于基2的Montgomery改进算法，采用模乘心动阵列结构，提出了一种双边沿触发串行计算的新结构，节约了面积，同时可以达到较高的时钟频率。模幂部分基于M-ary算法，减少了所需模乘运算的次数。并比较了这种实现方法与常见的L-R二进制幂算法的实现方式速度上的改进。     

一种面向多核处理器高效并行的Montgomery加密算法

经典 Montgomery 阶梯算法是提高椭圆曲线加密运算效率的有效方法之一。首先利用循环展开技术,提出了一种改进的 Montgomery 阶梯算法。然后根据 Montgomery 椭圆曲线加密算法的特点,在其读入数据环节采取数据并行方式进行处理;在其模幂运算环节采取任务并行方式进行处理。仿真实验结果表明,采用数据并行和任务并行2种方式,可有效提升椭圆曲线加密运算的效率。     

A New Improvement Method of Abel Inversion

A new improvement method of Abel inversion is presented for application in asymmetrical measured value that is obtained from plasma diagnostics on the toroidal plasma system. The local value is symmetry up and town circle section, and asymmetry from left to right. This new method is aimed at general measuring configuration, and need not assume integration chords to be parallel (for instance, pinhole configurations). The local value in the boundary of toroidal plasma is obtained by other methods. In the center part, the asymmetrical local value is expanded to Fourier-Bessel series, and Fourier terms include the information of asymmetry. The coefficients of the expansions are determined using least-square-fitting method. We finally obtain the distribution of the local value by using the synthesis of the value in the boundary and the value in center part.     

一种高效执行并行图像旋转的新方法

本文提出了一种在分布式并行机上有效地执行二维图像旋转的方法.算法的开发是在高级图像抽象的框架下进行的.文中阐述了利用在二维可分旋转技术的基础上新开发的高级抽象表达式,可以简捷地表示并行图像旋转,并可在分布式存贮并行体系结构上有效地执行.本文还对二维可分运算进行了误差分析,并提出了减小误差的补偿方案.     

A New Method for Asymmetrical Abel Inversion Using Fourier-Bessel Expansions

A new asymmetrical Abel inversion is presented for application in asymmetrical data which is obtained from plasma diagnostics on the toroidal plasma system. Asymmetry in the system exists in the direction along chord distribution. This new method is aimed at general measuring configuration, and need not assume integration chords to be parallel (for instance, pinhole configurations). In this new method, the asymmetrical local value is expanded to Fourier-Bessel series, and Fourier terms include the information of asymmetry, The coefficients of the expansions are determined using least-square-fitting method.     

一种实现CSFB的方法研究

探讨了一种电路域回落(CSFB)的实现方法,该方法可以避免对现网已经部署的访问移动交换中心服务器(VMSC)、网关移动交换中心(GMSC)升级改造,易于在现网部署。在本CSFB解决方案中,由归属用户服务器(HSS)执行呼叫重试功能,从组网来看,只需要增加一个Proxy移动交换中心(MSC)服务器,对现网已经部署的VMSC、GMSC没有改造要求。     

A Conjugate Direction Method for Geophysical Inversion Problems

In geophysical tomography, algebraic methods are often used to linearize the nonlinear problem of determining the characteristics of an underground region given measurements of the earth's attenuation to electromagnetic or seismic waves. In this way, a set of linear equations is developed such that the unknowns are the picture elements (pixels) of the region being scanned.Classically, these linear equations have been solved using the algebraic reconstruction technique (ART) algorithm. In this paper, a new algorithm that is a member of the set of conjugate direction (CD) methods is developed and comparisons are made between this algorithm and the ART algorithm for data arising from simulated electromagnetic probing. This new method, which we call the constrained conjugate gradient (CCG) algorithm, is shown to have a much faster convergence to a final solution than the ART algorithm. In addition, for applications involving high-contrast anomalies (for example, tunnel detection) the CCG is shown to have superior performance in locating the anomalous region for almost all test cases considered.     

A New Algorithm for High-Speed Modular Multiplication Design

Modular exponentiation in public-key cryptosystems is usually achieved by repeated modular multiplications on large integers. Designing high-speed modular multiplication is thus very crucial to speed up the decryption/encryption process. In this paper, we first explore how to relax the data dependency that exists between multiplication, quotient determination, and modular reduction in the conventional Montgomery modular multiplication algorithm. Then, we propose a new modular multiplication algorithm for high-speed hardware design. The speed improvement is achieved by reducing the critical path delay from the 4-to-2 to 3-to-2 carry-save addition. The resulting time complexity of our development is further decreased by simultaneously performing the multiplication and modular reduction processes. Experimental results show that the developed modular multiplication can operate at speeds higher than those of related work. When the proposed modular multiplication is applied to modular exponentiation, both time and area-time advantages are obtained.     

A New Inversion Technique for Apparent Resistivity Measurements

A new algorithm for interpreting apparent earth resistivity data obtained from depth sounding measurements is presented. The method is based on fitting the data to an N layer earth model with equal layer heights h where h is equal to the required depth resolution. The spectral reflection coefficient at the earth's surface for the model used is derived as a ratio of two polynomials, the coefficients of which are a function of the resistivity ratios of adjacent layers. This provides the theoretical basis for inferring the model parameters. Measures for improving numerical stability are suggested and applied to a few examples. Results show that the present algorithm is most suited for continuously varying resistivity depth profiles.     

一种反演地下介质参数的新算法

在探地雷达实际工程应用中,介质参数(主要是介电常数)是使用者正确定位地下目标深度或介质层厚度所必需的数据。该文提出一种基于MUSIC谱估计的地下介质参数反演算法,该算法通过对LFMCW GPR回波信号的时延和幅度估计,计算出精确的介质参数并进一步得到正确的地下介质结构。仿真结果表明：该文提出的反演算法在反演精确度上远远优于传统的电磁反演算法。     

基于阵列信息的二维轴对称电导率分布的有效反演方法

本文基于实际工程应用中的阵列感应测井仪（ＡＩＴ）的测量信息,利用变分坡昂迭代法（ＶＢＭ）,在非均匀背景介质中来重构和反演地层的电导率剖面。该方法基于非线性积分方程利用变分方法来建立反演方程,在反演迭代过程中,非均匀剪影介质中的格林函数无须更新,与变形玻昂迭代法（ＤＢＩＭ）相比其计算复杂性大大降低,文中仅利用沿井轴的ＡＩＴ响应对地层电导率进行反演,其胍演结果与起初地层电导率分布吻合的较好。