Skype走进学校

Skype是一款免费的互联网语音沟通工具.目前针对中国地区的版本是Tom-Skype,在http:∥WWW.tom.com可以下载.由于Skype通话质量非常清晰,甚至超过了传统电话,在PC到PC间通话是免费的,且注册使用非常简单,所以在互联网上已成风靡之势.基于Skype的功能特点,把Skype应用于校园网为教育教学服务,让我们眼前一亮.     

Skype安全性分析

Skype正越来越普及,并受到越来越多的关注。文章从通信安全的角度来分析Skype的安全特性,介绍了Skype通信加密的过程,讨论Skype使用加密的具体技术细节,在此基础上分析鉴定用户服务器身份以保护通信信息的安全,分析了几种常见攻击对Skype的可行性,对Skype的通信安全进行概括,并提出了使用中应注意的安全事项。     

Detailed Analysis of Skype Traffic

Skype is beyond any doubt the VoIP application in the current Internet application spectrum. Its amazing success has drawn the attention of telecom operators and the research community, both interested in knowing its internal mechanisms, characterizing its traffic, understanding its users' behavior. In this paper, we investigate the characteristics of traffic streams generated by voice and video communications, and the signaling traffic generated by Skype. Our approach is twofold, as we make use of both active and passive measurement techniques to gather a deep understanding on the traffic Skype generates. From extensive testbed experiments, we devise a source model which takes into account: i) the service type, i.e., SkypeOut calls or calls between two Skype clients, ii) the selected source Codec, iii) the adopted transport layer protocol, and iv) network conditions. Leveraging on the use of an accurate Skype classification engine that we recently proposed, we study and characterize Skype traffic based on extensive passive measurements collected from our campus LAN.     

基于Skype的网络教学系统

网络教学是指利用计算机及计算机网络为基础的教学系统,阐述以网络作为传输载体,并与Skype技术相结合,使学生和教师可以异地完成教学。     

Polycom商务型Skype视频协作解决方案

Polycom与微软公司宣布扩大双方的合作关系,Polycom将推出专为商务 Skype 构建的视频协作解决方案新系列Polycom R RoundTable R。Polycom R RoundTable R 100为这一新系列的首个产品,该解决方案适用于小规模办公环境,价格经济而易于使用：商务Skype和 Lync 2013的中小企业（SMB）客户只需登录其商务Skype账户,即可享受包括语音、视频和内容协作在内的丰富的协作体验。RoundTable 100只需数分钟即可完成安装并立刻开始使用,该产品专为中小型企业而设计,部署简单,并且易于使用和维护,因而用户无需IT人员的协助。     

Traffic analysis attacks on Skype VoIP calls

Skype is one of the most popular voice-over-IP (VoIP) service providers. One of the main reasons for the popularity of Skype VoIP services is its unique set of features to protect privacy of VoIP calls such as strong encryption, proprietary protocols, unknown codecs, dynamic path selection, and the constant packet rate. In this paper, we propose a class of passive traffic analysis attacks to compromise privacy of Skype VoIP calls. The proposed attacks are based on application-level features extracted from VoIP call traces. The proposed attacks are evaluated by extensive experiments over different types of networks including commercialized anonymity networks and our campus network. The experiment results show that the proposed traffic analysis attacks can greatly compromise the privacy of Skype calls. Possible countermeasure to mitigate the proposed traffic analysis attacks are analyzed in this paper.     

流特征的Skype流量识别

Skype流识别的研究大多局限于在静态载荷特征和通信机制,没有考虑网络流特征在Skype流量识别中的作用.提出了一种基于朴素贝叶斯分类的Skype流量识别模型.选择流的连接特征和实时特征作为分类特征集,根据流的连接特征组织网络流,再进一步根据流的包长度、平均发送间隔和突发带宽消耗等实时流特征识别Skype流量.在北京联通骨干网络上的实验表明该模型能有效地识别Skype流,是一种有效的Skype流识别算法.     

Analysis of information leakage from encrypted Skype conversations

Voice over IP (VoIP) has experienced a tremendous growth over the last few years and is now widely used among the population and for business purposes. The security of such VoIP systems is often assumed, creating a false sense of privacy. This paper investigates in detail the leakage of information from Skype, a widely used and protected VoIP application. Experiments have shown that isolated phonemes can be classified and given sentences identified. By using the dynamic time warping (DTW) algorithm, frequently used in speech processing, an accuracy of 60% can be reached. The results can be further improved by choosing specific training data and reach an accuracy of 83% under specific conditions. The initial results being speaker dependent, an approach involving the Kalman filter is proposed to extract the kernel of all training signals.     

Green Cell Phones and Mobile Skype Finally Arrive

This installment of New Products covers new green cell phones, a universal charger, cellular femtocells, Skype on mobile phones, a service that turns on street lights from your phone, and a de-identify caller ID.     

Skype网络流量测量及特征发现

针对越来越多P2P语音、视频传输应用给底层网络造成巨大通信压力的问题,提出Skype网络拓扑测量方案,分析Skype协议、通信机制、流量及行为特征。通过分析大量主动获取的节点数据和被动获取的Skype通信流量,总结出Skype网络的通信机制,发现部分Skype网络的流量特征、协议行为特征,经测试,在局域网环境下,该项方案能有效识别、管理Skype流量。     

Skype将推出付费电话会议服务

Skype宣布将推出付费的电话会议服务,该服务将支持多用户通话,并支持视频和文件共享。Skype目前的免费电话会议服务仅允许两名用户进行在线会议。Skype与软件公司Citrix合作推出付费的电话会议服务。Citrix公司把其在线会议软件GoToMeeting的一些技术整合到     

Skype网络电话技术探析

Skype网络电话技术是近年来兴起的对传统电信业冲击较大的一项技术,拥有全球近3亿的用户数,2012年被微软收购以来使用率上涨了58%,已成为全球最重要的网络通讯服务。对其网络结构及运行机制进行了深入探析,特别是用户登录过程、搜索机制等,为以后国内网络电话技术研究提供了借鉴和参考。     

基于趋势感知协议指纹的Skype加密流量识别算法

P2P技术极大地方便了互联网上的资源共享,在网络流量中比例最大且多以加密形式出现,但存在带宽消耗大、分享内容缺乏监管等弊端。准确快速识别基于P2P架构的Skype加密流量,对于提高网络服务质量、优化网络带宽分配、加强安全管控有着重要意义。在分析Skype信令交互和内容传输阶段流量统计特征的基础上,提出一种基于趋势感知协议指纹的Skype加密流量识别算法。通过定义趋势感知加权函数,真实反映了流量特征的变化趋势;利用异常相似度,对Skype加密流量进行实时检测。实验结果表明,该方法的精确度和实时性均优于经典的协议指纹算法和C4.5等最新的加密流量识别方法。     

On Metrics to Distinguish Skype Flows from HTTP Traffic

Skype is a Voice over IP (VoIP) Internet application that is gaining huge popularity in recent years. A key point to Skype popularity is its capability to dynamically adapt itself to operate behind firewalls or network proxies. A common way adopted by Skype to delude these network devices is to use port 80, normally expected to comprise HTTP traffic. In this paper, we propose metrics and investigate statistical tests intended to clearly distinguish Skype flows from HTTP traffic. We validate our study using real-world experimental datasets gathered at a commercial Internet Service Provider (ISP). Our experimental results suggest that the proposed methodology may be seen as a promising building block towards a system to detect general protocol anomalies in HTTP traffic.     

一种基于行为模式的Skype流量识别方法

Skype是一种基于P2P技术的VoIP客户端,其通讯协议不公开,且通讯内容加密,因此对Skype的流量识别不能采用传统的端口识别法及特征字检测法。首先对Skype的通信机制进行深入的探讨,并通过实际的数据包分析总结出Skype流量的行为模式,最后设计并实现了相应的识别模块对结论进行验证。     

一种基于Xgboost的Skype时间式隐信道检测方法

时间式隐信道利用数据包的包间时延来传递秘密信息,受网络时间特性复杂性的影响,网络隐信道的检测率低且虚警率较高.提出一种利用Xgboost模型的Skype时间式隐信道检测方法.在传统提取Skype时间序列的Markov转移特性、信息熵、包间时延的均值与方差、DCT系数、ε-相似度等特征的基础上,增加峰态、偏态和标准偏差的...     

Understanding internet recruitment via signaling theory and the elaboration likelihood model

A detailed model specifying the linkages between Internet recruitment websites and organizational attraction was examined. Participants (N = 581) viewed Fortune 500 company websites and responded to questions about the content and design of these websites and their resulting attitudes, fit perceptions, and organizational attraction. Results showed that recruitment website content and design influence attitudes toward the recruitment websites, organizational attitudes, and subsequently organizational attraction. The moderating effects of person-organization (P-O) and person-job (P-J) fit were examined. Two sets of hypotheses based on signaling theory (  and ) and the elaboration likelihood model ( Petty & Cacioppo, 1981) were largely supported. Consistent with signaling theory, the amount of job and organizational information on a recruitment website interacted with website usability, such that when less job information was presented, website usability played a greater role in predicting favorable attitudes towards the organization. Consistent with the elaboration likelihood model, when P-J fit was high, website aesthetics were less important in predicting attitudes towards the organization.     

Skype发送模型及其应用

为了提高Skype语音流的检测效率,在分析Skype流量特征和负载特征的基础上,提出了Skype语音源的发送模型.该模型体现了Skype发送端帧结构的特征,大大简化了接收端识别的过程.     

一种针对Skype时间特性拟合的网络隐写检测方法

网络隐写检测是实现网络可管可控的重要技术支撑,与传统网络隐写相比基于模型拟合的时间式隐写具有更高的隐蔽性,使其成为研究热点。近来研究者提出了一种拟合Skype应用时间特性的网络隐写方法,由于载体的广泛应用,该方法一经提出便受到极大关注,而目前尚无有效的检测方法。首先通过实验验证了该方法可抵抗基于信息熵的检测算法,进而提取网络数据流时间序列的Markov转移特性、信息熵、均值与方差、DCT(Discrete Cosine Transform)系数以及ε-相似度5种典型特征,最后通过BP(Back Propagation)神经网络进行分类给出检测结果。实验表明,所提检测方法针对此种隐写算法检测率可达99%,虚警率低于3%,同时通过多样性实验验证了所提方法的鲁棒性。