"音质"和"音色"

“音质”和“音色”是两个不同的术语,在某些场合极易混用。如通常说一个扬声器的音质很好,但一般不说扬声器的音色很好;说一个音乐厅、歌剧院的音质设计得很好,并不说音乐厅和歌剧院的音色很好。而在另一些场合用“音色”这个术语时,经常是说“小提琴音色”、“大提琴音色”、“钢琴音色”等等,在电子琴中也用     

"三网融合"、"云计算"、"物联网"点亮"信息亚运"

历届大型运动会的经验表明,高水平的体育盛会,要有高科技作为支撑.中国电信在对"信息亚运"的建设中,也将高科技融入其中,利用科技的突破创新,实现亚运各项工程的数字信息化. 中国电信有关负责人表示,在实施"信息亚运"的进程中,技术的创新应用占据了重要比重,主要体现在当前流行的"物联网"、"云计算"、"三网融合"等等.     

从"统计"到"理解",从"传输"到"认知"

今年是Shannon信息论问世的50周年．为了纪念这一伟大事件，本文回顾了它的杰出成就及其划时代贡献，也指出了这一理论不可避免的时代局限；着重评述了自Shannon信息论问世以来信息科学在世界范围内的主要进步，特别强调了这一领域的巨大变革和质的飞跃──从统计信息理论到全信息理论，从信息传输到信息认知，从通信理论到智能科学．作者认为，人们应当在科学上作好充分的准备，去迎接信息时代的新阶段──智能科学时代的到来．     

"韩流"退去"台风"来袭

90年代末,一部《蓝色生死恋》让无数的大陆观众第一次见识了韩剧的威力,舒缓的节奏、凄美的爱情、标致的俊男美女,不论你怎么换台,都还是想扭头再多看两眼.……     

"分体机"的"一体化遥控"

机顶盒与电视机的＂分体＂状态导致的遥控问题一直备受关注,能否让数字电视的遥控更加简化,是关系到下一代机顶盒市场表现的关键。本文针对如何在机顶盒上实现一体化遥控的技术要点作了一些提示,以期为数字电视用户端设备的生产和运营提供帮助,从而拉动机顶盒的消费市场。     

"音乐天使"再燃"激情"

记得去年第12期《视听技术》上，有一篇介绍加拿大“音乐天使”(La Pieta)女子乐团的文章。该乐团去年10月来华，在上海举办两场别开生面的演出。此后，推出了一款名叫“魔怪小提琴”(Infernal Violins)的CD、DVD专辑(碟号：AN28723)的专辑。这款由拿索斯旗下ANALEKTA公司出版的影音新品，无论演奏、表演和录音录像，都给我们留下鲜明的印象。     

选择"联通"选择"未来"

天下大势,合久必分,分久必合。这是自然规律,也是市场竞争的一条铁的法则。中国联通1994年诞生,引发中国电信市场的大改局,电信市场从此告别了垄断,引入了竞争,开始了黄金发展的十年。有学者近日指出:“移动市场由于打破了垄断,才有今天的繁荣局面。”今年农历年初,铁通划归国资委后,经历了数次拆分的中国电信市场终于形成了六大运营商并存的格局。不过,迹象显示,这种六头并存的格局可能又要被打破,电信业可能将重新洗牌:5月份,“中国电信四合二”再重组的消息骤然而降,一石激起千层浪。1 谜团显露生机有关“四合二”的传闻至今尚未得到证…     

一种基于扩展GHZ态的改进量子“乒乓”协议

In order to transmit secure messages, a quantum secure direct communication protocol based on extended three-particle GHZ state was presented, in which the extended three-particle GHZ state was used to detect eave sdroppers . In the security analysis, the method of the entropy theory is introduced, and three detection strategies are compared quantitatively by using the constraint between the information eavesdroppers can obtain and the interference introduced. If the eavesdroppers intend to obtain all information, the detection rate of the original "Ping-pong" protocol is 50% ; the second protocol used two particles of EPR pair as detection particles is also 50% ; while the presented protocol is 58% . At last, the security of the proposed protocol is discussed. The analysis results indicate that the protocol in this paper is more secure than the other two.     

Wireless secure enhancement with cooperative jamming

Secrecy capacity of intrinsically secure communication graph (iS-Graph) can be increased by reducing the signal quality of eavesdroppers with adding controlled interferences.The transmission of secret messages over wireless channels in which the legitimate nodes were aided by cooperative jamming was studied,and a secure communication graph with jamming,jS-Graph was proposed.First,the security properties of jS-Graph was characterized.Then,jamming strategies to confuse eavesdroppers were proposed.To tackle the nearby eavesdropper problem,a two-stage cooperative jamming strategy to jam the eavesdroppers near the source or the destination was applied.The results demonstrate that,with the aid of cooperative jamming the secure communication graph can lead to secrecy gains.These results help to clarify how the presence of eavesdroppers and the cooperative jamming can influence secure connectivity in wireless networks.     

一种基于Einstein-Podolsky-Rosen (EPR)序列的量子安全直接通信协议

为了提高量子安全直接通信协议的安全性并同时降低其成本,该文通过对协议中检测窃听过程的分析给出了一种有效的方法,并从量子安全直接通信和量子秘密共享两种角度验证了这种方法的可行性。合法通信者使用携带有秘密消息的传输粒子检测窃听,并且不会泄露任何秘密消息。分析表明,合法通信者在不用制备单独用来检测窃听的检测粒子情况下,不仅能够让协议的量子比特理论效率达到100%,而且可以确保其无条件安全。     

Security Problems in an RFID System

This paper focuses on the security and privacy threats being faced by the low-cost RFID communication system, the most challenging of which relate to eavesdropping, impersonation, and tag cloning problems. The security issues can be improved and solved by utilizing both prevention and detection strategies. Prevention technique is needed since it offers resistance capabilities toward eavesdroppers and impersonators. Detection technique is vital to minimize the negative effects of tag cloning threats. This paper proposes the use of both prevention and detection techniques to make RFID communication more secure. Lightweight cryptographic algorithm, which conforms to the EPC Class-1 Generation-2 standard, is used in the proposed mutual authentication protocol for RFID system to raise security levels. In addition, electronic fingerprinting system is deployed in the proposed solution as a detection method to distinguish counterfeit and legitimate tags.     

并行组合扩频通信的数据调制映射法和安全通信协议方式＊

并行组合扩频通信是一种高效率的新型扩频通信方式.本文提出了并行组合扩频通信的数据调制映射法,并以此为基础,给出了一种安全通信协议方式,既可作身份认证又有好的保密能力。     

对称环境下安全协议组件的安全属性分析

文章基于一种模块化的安全协议设计方法,定义了基本消息和基件的概念后,从研究安全协议的基件开始,将不同的基件适当复合后可得到具有特殊安全属性的组件,并运用BAN类逻辑对这些组件进行了形式化的分析。这些具有特殊安全属性的组件,在满足协议需求的同时,从底层开始保证了协议能够达到预期的安全目标,为安全协议的设计奠定了基础。     

Secure message transmission in mobile ad hoc networks

The vision of nomadic computing with its ubiquitous access has stimulated much interest in the mobile ad hoc networking (MANET) technology. However, its proliferation strongly depends on the availability of security provisions, among other factors. In the open, collaborative MANET environment, practically any node can maliciously or selfishly disrupt and deny communication of other nodes. In this paper, we propose the secure message transmission (SMT) protocol to safeguard the data transmission against arbitrary malicious behavior of network nodes. SMT is a lightweight, yet very effective, protocol that can operate solely in an end-to-end manner. It exploits the redundancy of multi-path routing and adapts its operation to remain efficient and effective even in highly adverse environments. SMT is capable of delivering up to 83% more data messages than a protocol that does not secure the data transmission. Moreover, SMT achieves up to 65% lower end-to-end delays and up to 80% lower delay variability, compared with an alternative single-path protocol––a secure data forwarding protocol, which we term secure single path (SSP) protocol. Thus, SMT is better suited to support quality of service for real-time communications in the ad hoc networking environment. The security of data transmission is achieved without restrictive assumptions on the network nodes’ trust and network membership, without the use of intrusion detection schemes, and at the expense of moderate multi-path transmission overhead only.     

结合全双工与协作干扰的无线网状网物理层安全策略

针对无线网状网中缺少窃听者先验知识不利场景中的安全连接问题,提出了一种结合全双工和协作干扰技术的物理层安全策略。利用全双工通信中的自干扰消除技术和协作干扰技术,提出的安全策略可有效劣化位于信息传播范围内包括潜伏在接收节点附近窃听者的接收性能。为保证信息的安全传输给出了协作干扰节点的选择方法,基于随机几何等数学方法导出了选定路径的安全连接概率表达式。性能分析和仿真结果表明,所提方法与仅基于全双工或协作干扰技术的方法相比,其安全性能有较大提升。     

基于W态与Bell态纠缠的QDKD方案

为了提高密钥分发效率,利用量子密集编码的原理设计了一种基于W态和Bell态纠缠的量子确定性密钥分发方案(Quantum Deterministic Key Distribution, QDKD)。方案中,消息发送者Alice通过对持有粒子实施幺正操作实现确定性密钥的编码,接收方Bob利用粒子间联合测量获得确定性密钥。除去用于窃听检测的粒子,制备的粒子全部用于消息传输,每发送5个粒子可以实现5bits确定性密钥的分发。最后,利用信息论方法对方案进行安全性分析,结果表明,方案是安全可靠的,任何窃听行为能够被及时发现。     

Privacy‐preserving registration protocol for mobile network

In this paper, we propose a novel privacy‐preserving registration protocol that combines the verifier local revocation group signature with mobile IP. The protocol could achieve strong security guarantee, such as user anonymity via a robust temporary identity, local user revocation with untraceability support, and secure key establishment against home server and eavesdroppers. Various kinds of adversary attacks can be prevented by the proposed protocol, especially that deposit‐case attack does not work here. Meanwhile, a concurrent mechanism and a dynamical revocation method are designed to minimize the handover authentication delay and the home registration signals. The theoretical analysis and simulation results show that the proposed scheme could provide high security level besides lightweight computational cost and efficient communication performance. For instance, compared with Yang's scheme, the proposed protocol could decrease the falling speed of handover authentication delay up to about 40% with privacy being preserved. Copyright © 2012 John Wiley & Sons, Ltd.