Pollard p-1因子分解的DNA计算机算法

如何有效地对大整数进行因子分解是数学上的一个难题.给出了基于分子生物技术的因子分解问题的DNA计算机算法.算法以Pollard p-1算法为基础,利用DNA分子生物操作完成加、减、乘、除运算,实现平方-乘以及欧几里德算法,产生并得到最终解.基于分子生物学的实验表明,该算法是可行和有效的.     

Robert Q. Pollard.

From Robert Q. Pollard's national leadership in deafness and mental health service delivery, advocacy, research, and training and his innovative multidisciplinary mental health traineeship program exclusively for deaf individuals to his establishment of a vibrant special interest section on deafness within APA's Division of Rehabilitation Psychology, he has led the way to providing full access to the profession and to the services of the profession for deaf individuals. His commitment to and effective advancement of a psychology open to and appropriately serving deaf individuals and other persons with disabilities substantially advances psychology in the public interest and fulfills our discipline's highest aspiration: to advance human welfare. This journal discusses the life and contributions of Robert Q. Pollard which enabled him to win the Psychology in the Public Interest Award in 1994. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Montgomery模乘在3种分解算法中的应用

文章针对Montgomery模乘的特点,分别对Pollard Phro、P-1和P 1算法进行适当的改造,使得底层的经典模乘运算可以由Montgomery模乘来代替。实验结果表明,在使用了Mont-gomery模乘之后,这3种分解算法的分解速度都得到了极大地提升。     

Interdisciplinary Analysis of Hedgerow Network Landscapes' Sustainability

Hedgerows with pollarded trees are still emblematically shaping many agricultural landscapes in Western Europe; they are part of our heritage but their future is uncertain due to the enlargement of fields and loss of firewood use. As a consequence the sustainability of these agricultural landscapes is questioned. We studied changes in hedgerow management in a long-term ecological site in Brittany, France with an interdisciplinary approach. Importance, spatial distribution and relationship with the agricultural system have been assessed over 11 years in three contrasted hedgerow network landscapes, while management practices and farmers' perception were studied from an anthropological point of view. Two apparently opposed trends were found: first, an apparent decrease in the interest of farmers for hedgerows witnessed by the diminishing of the rate of pruning; second, changing attitudes of farmers not necessarily toward hedgerow abandonment but rather toward the production of novel shapes for pruned trees.     

基于SIMD指令的ECC攻击算法研究

ECC是目前比特安全强度最高的公钥密码体制,对它的攻击需要大量的计算资源.基于SIMD指令和bitslice数据结构设计了GF(2m)上的ECC攻击算法,并对核心模块进行了优化.利用比特交换的方法提出了一个bitslice数据结构和非bitslice数据结构的快速转换算法,计算复杂度为O(nlogn),对算法简单调整后可适用于二元矩阵的快速转置;利用Karatsuba-Ofman算法和Montgomery并行求逆对椭圆曲线底层运算进行了优化,分析了计算复杂度.对ECC挑战中的ECC2-109和ECC2-131进行了测试,在单核Pentium 4 3.0GHz平台上的迭代速度分别为1 330 000次/s和980 000次/s,攻击效率比Chris Monico的公开程序提高了1倍.     

F2m上并行Pollard rho算法的优化实现

并行PoHard rho算法是目前攻击椭圆曲线密码体制（Elliptic Curve Cryptosystem,简称ECC）的最好算法,国内外的研究十分活跃。本文首先介绍了攻击F2^m上ECC的并行Pouard rho算法及我们的实现流程,然后给出了核心基本运算（包括求逆、一般乘挚、平方、求模等）的优化算法。实验数据表明,根据本文优化算法编制的MPI并行程序在多机上加速比良好,运算速度优于互族网上公开的程序。     

两类整数分解算法的分析与改进

给出了整数分解的两种算法,试除法和Pollard算法.根据素数分布的规律,通过减少试除次数提高了试除法运算效率,使得其性能显著提高;对Pollard算法进行分析后,变换随机序列产生式并重启算法使算法运行更稳定有效.给出了这两类改进算法的运行时间对比表,结果表明,改进的试除法在分解32位内小整数效果更佳而改进的Pollard算法在分解32位以上大整数有明显的优化.