浅析ESC的次原像攻击和原像攻击

文献[1]给出了一个新的密码建构ESC,本文简单讨论了该建构的次原像攻击和原像攻击,得出了一般情况下有以下结论:不管f为随机变换还是随机置换,当原像的消息块数较少时,则次原像攻击产生的次原像消息的长度会比原像多出以2为底的指数级块数;不管f为随机变换还是随机置换,则原像攻击结果可能没有原像或者产生原像消息的长度为以2为底的指数级块数。由此可知对ESC进行次原像攻击和原像攻击的实效性不强。     

基于MAC的无线传感器协议的改进

无线传感器TEEM(Traffic aware,Energy efficient MAC)协议是在MAC协议基础上以节量为目的流量自适应的协议.针对S-MAC(sensor MAC)协议的定期监听/睡眠模式中存在的耗能大的缺点,提出T-MAC(timeour MAC)协议.该协议是可以实现节点消息的自适应功能,从而降低耗能.仿真实验结果表明:该协议能效高,稳定性好.     

基于 MATLAB 的 MAC 序列相关特性仿真分析

MAC序列具有良好的相关特性,MATLAB在电子、通信、军事雷达等技术中,是一种很好的仿真应用工具.文章主要研究了基于MATLAB的MAC序列相关特性的仿真分析方法,给出了MAC序列相关特性MATLAB仿真程序和不同长度MAC序列的相关特性仿真图,并且对仿真结果进行了分析比较.MATLAB仿真软件在仿真过程中也充分发挥了软件本身的强大功能.     

NTRU公钥密码体制及其算法的优化

NTRU(NumberTheoryResearchUnit)是1996年提出来的一种新的公钥密码体制,其安全性取决于从一个非常大的维数格中寻找很短向量的困难性,它很好地解决了公钥密码体制的最大瓶颈———速度问题,这使它有着非常广泛的应用前景,成为新一代最优秀的公钥密码体制,本文主要介绍了NTRU公钥密码体制并对其算法进行了优化设计,从而使NTRU能得到更好的应用.     

改进MAC多安全策略组合方法的设计

针对支持多安全策略访问控制框架形成最终安全决定存在冲突及有效组织多个安全策略的问题,本文分析了当前主要访问控制框架的特点,提出了改进MAC多安全策略组合方法,引入了表达式匹配模式,改进了基于控制标识的安全决定策略,解决了访问控制框架在支持多安全策略时执行效率低、缺乏适应性的问题.     

基于零知识证明和M-H背包问题的身份识别技术研究

零知识证明的思想在密码学领域应用非常广泛。基于该思想和M-H背包公钥密码系统,创造性地提出了一种应用于该加密算法中的身份识别方案。该识别方案可用于发送方向接收方发送加密消息时,接收方对发送方身份的鉴别和认证。这是一个交互式的证明过程,可以防止身份的假冒。就其实施的可行性进行了证明,并分析和总结了方案存在的一些局限性。     

区块链上的通用钱包设计与实现

区块链技术是近年来兴起的一类计算机应用技术,不同的基于区块链的密码货币的产生,引发了对密码货币的管理问题。现有的专用钱包模式要求使用多币种的用户下载不同钱包进行资产管理。基于三层架构思想,设计了一个通用钱包的实现架构,以实现对多种密码货币的管理。通过所实现的通用钱包原型,验证了通用钱包架构的可行性。     

智力过山车

1.一只小狗五天吃100块饼干,如果它每天比前一天多吃六块饼干,那么,它第一天吃多少块饼干呢?(冉阳推荐)2.小明的妈妈有一个密码箱,妈妈让小明打开:密码是六位数。介于800000到900000之间。千位上是0,十位上是4,百位和个位数相同。密码的十万位、万位、千位上的数字组成的三位数除以百位、十位上的数字组成的两位数,商是35。大家快帮小明想想,密码是多少?(付岳推荐)     

一种优化的多媒体消息获取方法

针对多媒体消息群发业务中多个目的用户因获取相同的多媒体消息而使得无线应用协议网关（WAP）和彩信中心（MMSC）之间网络带宽被大量重复内容所占用的问题,提出了一个解决方案,即一种优化的多媒体消息获取方法：在通告下发时,附上多媒体消息的标识（MSGID）;当用户获取时,根据MSGID在WAP缓存中进行获取。笔者首先阐述了该方法的技术背景,再详细介绍了该方法的关键技术和具体实施方案。通过本方法,在不增加MMSC和WAP网关的硬件投入的情况下,提高了设备对群发多媒体消息的处理性能以及多媒体消息的群发效率,具有广阔的应用前景。     

基于JAVA的信息传输技术研究

随着计算机应用系统的广泛使用,在一个系统中通常会用两台或者多台服务器组成一个应用的处理平台,这涉及多台服务器网络之间信息如何共享、如何传递的问题,它是在系统中信息如何传输及解析的问题。JAVA高效准确地采用TLV消息格式的原理及方法,实现对信息的解包、打包。通过JAVA的Socket传输机制建立了非阻塞状态的服务端和客户端(C/S模式),实现了消息在网络内的传输和共享。     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

Western and Eastern culture differences in commercial field

The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity.     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

风的曲线

Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose.     

团图为数的图中的闭团贯数

Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.