基于比特重组快速模约简的高面积效率椭圆曲线标量乘法器设计

针对现有椭圆曲线密码标量乘法器难以兼顾灵活性和面积效率的问题,该文设计了一种基于比特重组快速模约简的高面积效率标量乘法器。首先,根据椭圆曲线标量乘的运算特点,设计了一种可实现乘法和模逆两种运算的硬件复用运算单元以提高硬件资源使用率,并采用Karatsuba-Ofman算法提高计算性能。其次,设计了基于比特重组的快速模约简算法,并实现了支持secp256k1, secp256r1和SCA-256(SM2标准推荐曲线)快速模约简计算的硬件架构。最后,对点加和倍点的模运算操作调度进行了优化,提高乘法与快速模约简的利用率,降低了标量乘计算所需的周期数量。所设计的标量乘法器在55 nm CMOS工艺下需要275 k个等效门,标量乘运算速度为48309次/s,面积时间积达到5.7。     

基于XML的综合网管对象数据交换

基于XML的Wed Services技术非常适合解决综合网管通信系统不同子系统之间互联、互通、互操作并建立完整的业务管理信息模型。文章介绍了在综合网管系统中基于XML中间件的数据交换(XMI)的实现。     

基于SNMP的一种Subagent模型的设计与实现

提出了基于SNMP协议的被管对象的一种比较通用的Subagent模型,该Subagent帮助网络管理站收集被管对象的可管信息,并在必要时发送告警信息给网络管理站。     

SNMP协议及其在智能家庭网络中的应用研究

通过分析智能家庭网络技术中现存及正在发展的相关技术标准,对智能家庭网络模型的设计及实现方案进行了研究,并提出了运用SNMP管理智能家庭网络的技术实施方案。     

两方有理数多重集的保密计算

集合的安全多方计算(SMC)在联合数据分析、敏感数据安全查询、数据可信交换等场景有着广泛的应用。该文基于有理数的几何编码,结合保密内积协议,首次提出了有理数域上两方多重集交集和并集的保密计算协议。应用模拟范例证明了协议在半诚实模型下的安全性,分别通过理论分析和仿真测试验证了协议的高效性。与现有协议相比,所设计协议无需给定包含所有集合元素的全集,可以保护集合势的隐私性,且在协议执行过程主要使用乘法运算,达到了信息论安全。     

Single-angle all-bolted shear connections

This paper describes an experimental test of 19 full-scale single-angle all-bolted shear connections. The primary purpose of the study was to determine the shear strength of the two bolt groups associated with the two legs of the connection angle. The tested connections were made of an equal-leg angle and a vertical row of bolts at each leg. The angle had a leg width of 102 mm and a thickness of 9.5 mm. The bolts were 19 mm diameter high-strength A325 bolts. The number of the bolts in one vertical row was from 2 to 8 inclusive. The observed failure mode of the tested connections was the shear rupture of one of the bolt groups. The test found torsional or lateral restraints to the supported beam had a significant impact on the load carrying capacity of the connections. Test results indicated that the current North American design practices could lead to underdesigned single-angle connections having the number of bolts less than or equal to three. Furthermore, a yield line method was adopted for estimating the connection moment at strength limit state.     

Some experiments with a simple tabu search algorithm for the manufacturer's pallet loading problem

The manufacturer's pallet loading problem consists in arranging, orthogonally and without overlapping, the maximum number of boxes with dimensions (l,w) or (w,l) onto a rectangular pallet with dimensions (L,W). This problem has been successfully handled by block heuristics, which generate loading patterns composed by one or more blocks where the boxes have the same orientation. A common feature of such methods is that the solutions provided are limited to the so-called first order non-guillotine patterns. In this paper we propose an approach based on the incorporation of simple tabu search (without longer-term memory structures) in block heuristics. Starting from an initial loading pattern, the algorithm performs moves that increase the size of selected blocks in the current pattern; as a result, other blocks are decreased, eliminated or created. Computational results indicate that the approach is capable of generating superior order optimal patterns for difficult instances reported in the literature.     

From a simple elimination ordering to a strong elimination ordering in linear time

We present a linear time algorithm for transforming a simple elimination ordering of a strongly chordal graph into a strong elimination ordering.     

智能卡SPA＆DPA攻击

智能卡是一种可防止被入侵设计的设备，为了防止攻击者藉由边际信道泄漏信息，如功率消耗、执行时间、故障时的输出与输入行为、电磁辐射、功率尖峰情形等信息攻击智能卡，必须采取一些防备措施。本文主要介绍攻击智能卡的简易功率分析（SPA），微分功率分析（DPA）。这些技术已被广泛地使用于窃取智能卡保护数据的技术上，提供这些技术的概略性观念，使我们知道问题所在，进一步想出对策，促使我们设计出更安全的智能卡。     

Parallel implementation of molecular dynamics simulation for short-ranged interaction

A parallel molecular dynamics simulation method, designed for large-scale problems, employing dynamic spatial domain decomposition for short-ranged molecular interactions is proposed. In this parallel cellular molecular dynamics (PCMD) simulation method, the link-cell data structure is used to reduce the searching time required for forming the cut-off neighbor list as well as for domain decomposition, which utilizes the multi-level graph-partitioning technique. A simple threshold scheme (STS), in which workload imbalance is monitored and compared with some threshold value during the runtime, is proposed to decide the proper time for repartitioning the domain. The simulation code is implemented and tested on the memory-distributed parallel machine, e.g., PC-cluster system. Parallel performance is studied using approximately one million L-J atoms in the condensed, vaporized and supercritical states. Results show that fairly good parallel efficiency at 49 processors can be obtained for the condensed and supercritical states (∼60%), while it is comparably lower for the vaporized state (∼40%).