安全协议的时限责任分析

本文针对安全协议中的时限责任问题,提出结合责任性与新鲜性来分析时间标记.这种思路体现在我们新的时限逻辑框架中,比较Kudo^[8]的方法,新的逻辑体系因为有对消息完整性的判断,能更有效地防止消息的篡改与重发攻击,且更加简洁和实用.     

对基于TCP/IP协议的网络攻击的分析

首先对网络攻击的种类和所分析协议的形式进行了阐述,接着主要分析了在不需要多少攻击资源的情况下攻击者所进行的基于ICMP、TCP协议上的网络攻击,最后提醒人们要有网络安全意识。     

Analyzing Control Traffic Overhead versus Mobility and Data Traffic Activity in Mobile Ad-Hoc Network Protocols

This paper proposes a general, parameterized model for analyzing protocol control overhead in mobile ad-hoc networks. A probabilistic model for the network topology and the data traffic is proposed in order to estimate overhead due to control packets of routing protocols. Our analytical model is validated by comparisons with simulations, both taken from literature and made specifically for this paper. For example, our model predicts linearity of control overhead with regard to mobility as observed in existing simulations results. We identify the model parameters for protocols like AODV, DSR and OLSR. Our model then allows accurate predictions of which protocol will yield the lowest overhead depending on the node mobility and traffic activity pattern.     

Synthesizing active filters

The primary purpose of this article is to present a unified, comprehensive survey of accomplishments in the field of network synthesis for linear, lumped, and finite networks from 1965 through early 1968.* Because of the large number of contributions made during this period, only a sampling of the many significant works is presented here, with much of the material in the form of results. It is the author's hope that the extensive list of references included will be useful in providing the additional information necessary.     

Terminal Protocols

Terminal protocols provide basic services for the users of computer networks. This paper presents a survey of the architecture and mechanisms used in current terminal protocols. The paper disusses both parametric terminal protocols such as the CCITT X.3, X.28, and X.29 and virtual terminal protocols, such as the ARPANET TELNET protocol. Many of the problems encountered in terminal protocols recur in more complex forms in the more sophisticated protocols.     

Synthesizing embedded speed-optimized architectures

A global optimization approach to high-level synthesis of speed-optimized embedded VLSI architectures is presented. Two mathematical integer programming (IP) models are presented. The first simultaneously selects types of functional units, performs scheduling tasks, and allocates hardware. The second additionally minimizes latency and optimally selects a clock period simultaneously with scheduling and allocation. By exploiting the problem structure, using polyhedral theory, the size of the search space of both IP models is decreased, thus improving the IP solution efficiency. This approach breaks new ground by simultaneously scheduling and allocating with complex and asynchronous interface constraints, to minimize both the average execution time and the area, automatically minimizing latency by optimally selecting the clock period and types of functional units (including chained operations), and synthesizing globally optimal architectures of embedded VLSI chips in practical CPU execution times     

IP安全结构、协议及分析

以Internet RFC为背景,描述了用于IPv4和IPv6的安全结构及协议,其中包括:安全协议SA、密钥管理、IP数据报安全封装ESP和认证AH,分析了上述机制的安全性,给出其待解决的问题。     

Specification and Validation of Protocols

Complex protocols are used to coordinate remote activities in computer networks. To insure proper operation, formal techniques of protocol definition and validation have been proposed, and developed to the point that they can be applied to actual protocols. However, much work remains to be done in order to cope with protocols of ever-increasing complexity; in particular, those coordinating the activities of many interacting entities. The characteristics that determine the applicability of the different specification and validation techniques to a protocol will be discussed. We will define the "topology" of a protocol, and treat also protocols that are intended to work in a variety of configurations, as well as configurations which may change in time (i.e. "evolving topologies"). Finally, based on this new general point of view, a short survey of specification and validation techniques will be presented, and the extensions needed to handle complex protocol characteristics will be discussed.     

安全电子邮件协议

一、PGP PGP(Pretty Good Privacy)是针对电子邮件在Internet上通信的安全问题而设计的一种公钥加密系统.PGP包含4个密码单元:单钥密码(IDEA)、双钥密码(RSA)、单向杂凑算法(MD-5)和一个随机数生成算法.PGP的用户拥有一张公钥列表(key ring),列出了所需要通信的用户及其公钥.PGP最初被设计为一个独立于邮件客户端的程序,邮件在发送前被作为附件进行加密.图l是利用PGP在Internet上通信的示意图.     

Physical Level Protocols

The physical level is the most basic protocol level in the hierarchy of data communication protocols. This level covers the physical interface between devices and the rules by which bits are passed from one to another. These devices may be, for example, a data terminal equipment (DTE) and a data circuit-terminating equipment (DCE, e.g., a modem). This paper describes the physical level and the national and international standards that have been developed for this level. Included are insights into the development of recently adopted physical level protocols.     

视频后期合成与像素

对像素、分辨率和电视制式概念的阐述,提出视频后期合成的格式及分辨率设置。以常用软件Adobe Potoshop（图像处理）Adobeaftereffcts（视频处理）图示说明像素、分辨率和视频合成之间的关系,分析视频合成过程中变形、抖动、效果差的现象。     

Synthesizing Hardware from Dataflow Programs

The MPEG Reconfigurable Video Coding working group is developing a new library-based process for building the reference codecs of future MPEG standards, which is based on dataflow and uses an actor language called Cal. The paper presents a code generator producing RTL targeting FPGAs for Cal, outlines its structure, and demonstrates its performance on an MPEG-4 Simple Profile decoder. The resulting implementation is smaller and faster than a comparable RTL reference design, and the second half of the paper discusses some of the reasons for this counter-intuitive result.     

浅析RIP和OSPF协议的工作原理

本文主要分析了路由器资讯协议（RIP）和开放式最短路径优先（OSPF）协议两种网络协议的工作原理,探讨了这两者的之间的区别以及缩短收敛时间的几项改进技术。文章中还阐述了最小开销路由选择在单一服务器网络中的影响以及源路由选择机制在提高网络效率中是如何发挥作用的。     

IMS框架体系及协议分析

IMS是近年来网络融合的热点标准之一.本文首先对IMS整体框架结构进行描述,分析主要的功能实体.然后通过几种典型呼叫流程阐述实体间的关系.最后介绍了两种IMS中的重要协议:SIP和Parlay.     

GSM网络接口协议分析

通过对GSM数字移动通信系统的结构、系统中各网络模块单元及其接口问的信令协议进行研究,分析了GSM的各个组成部分的功能和各接口之间的关系,阐述了相关的协议流程.并以一个移动用户作为被叫的完整呼叫流程作为例子,从而给出了GSM系统语音呼叫的完整流程,说明了GSM系统的工作过程.为下一步对GSM系统的升级演进提供了理论依据.     

Method of Synthesizing Nonuniform Waveguides

A method is proposed for the synthesis of continuous nonuniform waveguides with rectangular cross section so that they show desired electromagnetic properties for discrete frequencies when excited by the TE/sub 10/ mode. Starting from a uniform structure with known properties, the shape of the nonuniform waveguide is attained step by step by small systematic deformations. To show the feasibility of the method proposed, the mathematical formalism and numerical results are presented for reactive one-ports and filters with simple properties. In these cases, the problem is reduced to the solution of an equivalent resonator problem, i.e., a nonuniform waveguide resonator is developed for which a certain set of resonance modes occur at desired frequencies.     

无线寻呼协议及网际通信

讨论了 5种主流寻呼体制的编码特色、传输内容、抗衰落误码、漫游能力、非基本业务、体制兼容性、升级过渡等技术性能 ,从发展角度分析了它们的应用状况。另外 ,还介绍了不同生产厂家寻呼终端之间组网、寻呼网与计算机之间的连接以及 Internet等业务通过无线设备传递方面的工业标准协议     

多媒体通信控制协议

比较研究了三种用于多媒体通信控制的协议，探讨了今后多媒体通信控制协议的发展趋势。     

DCNA Higher Level Protocols

This paper explains a philosophy for modeling the higher level communication functions into a network architecture for heterogeneous computer networks called Data Communication Network Architecture (DCNA), the logical structure of the architecture, and several protocols based on it. To specify higher level protocols among computers of different types, DCNA defines a logical model of a computer network consisting of three submodels: the basic model, the logical network model, and the virtual network model. The basic model represents a logical view of the network resources, e.g., processing power, files, data bases, I/O devices, and a layered structure for the basic mechanisms for accessing such resources, which incorporate the concept of sublevels as well as levels. The logical network model describes the mechanisms for unified management of network resources. The virtual network model describes the mechanisms for using network resources. The. common use of network resources, by several sets of interrelated applications is made easier by treating the logical network and the virtual network separately. These models form the basis for the stipulation of higher level protocols, such as network management protocols, message transfer protocols, virtual terminal protocols, and virtual file system protocols.     

蓝牙技术的协议体系

蓝牙技术规范是蓝牙技术发展的根本,蓝牙协议体系是蓝牙技术规范的关键部分,对蓝牙技术协议体系结构和具体的协议进行了介绍.