基于CA的安全组播源认证方案研究

组播提供了一种发送者同时发送信息到多个接收者的高效通信机制。源认证是组播通信系统的重要安全问题。接收方在验证了消息来源后方可接收消息。本文分析了现有的两类源认证后，提出了一种基于CA的安全组播源认证新方案。     

基于抗碰撞函数和分组认证树的组播源认证方案

组播源认证是安全组播要解决的重要问题之一。文章提出了一种基于抗碰撞函数和分组认证树的组播源认证方案,重点描述了消息包的构造和验证过程,并分析了这种源认证方案的安全性和可验证概率。     

基于Tornado码的安全组播源认证方案

组播通信具有动态性和数据传送的不可靠性 ,如何在高丢包率的网络中对组播发送源进行高效认证是安全组播中的一个重要研究方向 .提出了一种对由组播分组哈希认证信息构成的链采用 Tornado抗丢包编码的源认证方案 .该方案减少了每个分组需携带的哈希认证信息大小 ,并在高丢包率的情况下能够得到很高的成功验证概率 .实验仿真的结果表明 ,在相同大小的认证信息下 ,本方案在成功验证概率上优于 EMSS( Efficient Multi- chained Stream Signa-ture)源认证方案     

基于频道跳变的安全特定源组播通信

提出了一种基于组播频道跳变的安全特定源组播通信方案。通过以不定长周期改变特定源组播频道的组地址,解决了阻止恶意主机跟踪、加入特定源组播频道接收组播流量、对组播路由基础设施实施DoS攻击等问题。仿真数据表明,该方案具有较好的可扩展性和易实施性。     

流媒体组播安全的设计与实现

讨论了多媒体通信系统的组播安全问题,提出了一整套结合高级加密标准AES的流媒体系统组播安全的方案,解决了用户安全注册、源认证、组成员认证以及视频数据保密等问题。并分析了如何在流媒体服务器端、组管理服务器端与客户端实现,在组管理服务器端给出了一种改进的身份认证方法,该方法可抵抗字典口令攻击。     

组播用户安全管理系统设计与实现

为了克服IP组播模型的开放性,使得在现有互联网条件下能够为组播管理者提供用户对频道的访问控制,在原有安全组播模型的基础上,提出了一种基于IPv6网络环境的组播用户安全管理系统模型的设计方案。该方案采用钩子(hook)机制在接入路由器上挂载了认证与访问控制模块,任何想要监听组播流的用户,都要通过该模块进行身份认证与频道访问权限的判定,从而实现了基于频道的组播用户安全管理。并在教育科研骨干网中实验验证了该系统的身份认证和访问控制功能。     

基于IPv6的SSM的MLDv2技术的研究

随着组播技术的发展,特定源组播已作为一种切实可行的通信模型。本文在探讨特定源组播和组播侦听发现协议的工作原理和体系结构的基础上,研究了基于组播侦听者的组播侦听发现协议的实现机制和内核流程,并提出了组播侦听者的接口状态转化问题。     

基于SIP的安全组播

组播业务的实施离不开组播安全。文中提出了一种使用会话初始化协议(SIP)作为信令实现安全组播的方法,该方法利用SIP协议身份验证机制、S/MIME加密与签名、会话参数协商能力,提供了组播源和接收者访问控制、组播源认证以及安全通信。该方法具有安全性高、运行稳定、扩展性好的优点,并能轻松移植到IPv6下运行。     

基于SIP的安全组播

组播业务的实施离不开组播安全。文中提出了一种使用会话初始化协议（SIP）作为信令实现安全组播的方法．该方法利用SIP协议身份验证机制、S／MIME加密与签名、会话参数协商能力，提供了组播源和接收者访问控制、组播源认证以及安全通信。该方法具有安全性高、运行稳定、扩展性好的优点，并能轻松移植到IPv6下运行。     

一种新的动态组播源认证方案

组播作为一种非常重要的网络技术,具有减少网络拥塞等诸多优点,必将得到广泛的使用.但缺乏安全机制严重限制了组播在各种网络业务中的应用和推广.源认证作为安全组播的核心问题之一倍受关注.简要介绍了现存的组播源认证方案,指出其优点和缺点.分析了组播源认证目前所面临的问题,探讨和总结了组播源认证的研究现状及发展趋势.同时,基于流签字认证技术,提出了一种新的动态组播源认证方案,该方案通过接收方对丢包率的反馈信息动态调整算法的步长,根据网络的实时状态,采用最合适的流签名算法,减少了哈希运算的次数及对缓存的需求,提高了认证速度,同时降低了通信量,缓解了网络拥塞.最后与相关的方案进行了性能分析和对比.     

基于IPSec的组播数据源认证设计方案

组播技术在面向组的应用中越来越多地使用,但是组播数据源认证问题却一直没有很好的解决方案.IPSec是解决IP层安全问题的协议,目前IPSec协议已经越来越多地用于组播应用中,在对IPSec的安全组播主机系统框架进行研究的基础上,提出了基于一次性签名的组播数据源认证方案,重点解决了组播数据源认证设计的困难,这个方案能够达到组播数据源认证的安全性与性能两个方面的要求,尤其在抗抵赖和计算量两个方面作了改进.     

A hybrid scheme for multicast authentication over lossy networks

For multicast communication, authentication is a challenging problem, since it requires that a large number of recipients must verify the data originator. Many of multicast applications are running over IP networks, in which several packet losses could occur. Therefore, multicast authentication protocols must resist packet loss. Other requirements of multicast authentication protocols are: to perform authentication in real-time and to have low communication and computation overheads. In the present paper, a hybrid scheme for authenticating real-time data applications, in which low delay at the sender is acceptable, is proposed. In order to provide authentication, the proposed scheme uses both public key signature and hash functions. It is based on the idea of dividing the stream into blocks of m packets. Then a chain of hashes is used to link each packet to the one preceding it. In order to resist packet loss, the hash of each packet is appended to another place in the stream. Finally, the first packet is signed. The proposed scheme resists packet loss and is joinable at any point. The proposed scheme is compared to other multicast authentication protocols. The comparison shows that the proposed scheme has the following advantages: first, it has low computation and communication overheads. Second, it has reasonable buffer requirements. Third, the proposed scheme has a low delay at the sender side and no delay at the receiver side, assuming no loss occurs. Finally, its latency equals to zero, assuming no loss occurs.     

高效的动态组播群通信认证签字方案

由于组播群组的动态性和数据传送的不可靠性,相对于点到点通信,组播通信的安全认证更为复杂.在组播数据发送源认证问题中,签字的速度和长度是实现认证的主要障碍.为了解决这个问题,通过引入新的认证技术——认证矩阵,提出了一个有效的适用于大数量动态的群组和不可靠数据传送的组播认证签字方案.相对于目前的组播包认证方案,该方案可显著地降低签字长度,提高签字速度,并可提供不可抵赖服务,可应用于如多媒体数据传输、多方会议以及远程教育等广泛的应用领域.     

Multicast receiver access control by IGMP-AC

IP multicast is best-known for its bandwidth conservation and lower resource utilization. The present service model of multicast makes it difficult to restrict access to authorized End Users (EUs) or paying customers. Without an effective receiver access control, an adversary may exploit the existing IP multicast model, where a host or EU can join any multicast group by sending an Internet Group Management Protocol (IGMP) join message without prior authentication and authorization. We have developed a novel, scalable and secured access control architecture for IP multicast that deploys Authentication Authorization and Accounting (AAA) protocols to control group membership.The principal feature of the access control architecture, receiver access control, is addressed in this paper. The EU or host informs the multicast Access Router (AR) of its interest in receiving multicast traffic using the IGMP protocol. We propose the necessary extensions of IGMPv3 to carry AAA information, called IGMP with Access Control (IGMP-AC). For EU authentication, IGMP-AC encapsulates Extensible Authentication Protocol (EAP) packets. EAP is an authentication framework to provide some common functions and a negotiation of the desired authentication mechanism. Thus, IGMP-AC can support a variety of authentications by encapsulating different EAP methods. Furthermore, we have modeled the IGMP-AC protocol in PROMELA, and also verified the model using SPIN. We have illustrated the EAP encapsulation method with an example EAP method, EAP Internet Key Exchange (EAP-IKEv2). We have used AVISPA to validate the security properties of the EAP-IKEv2 method in pass-through mode, which fits within the IGMP-AC architecture. Finally, we have extended our previously developed access control architecture to accomplish inter-domain receiver access control and demonstrated the applicability of IGMP-AC in a multi-domain environment.     

以太网交换机的源指定组播方案

针对边缘网中组播数据转发效率不高的问题,提出以太网交换机的源指定组播方案。在该方案中,交换机利用对IGMPv3报文的嗅探实现指定源的组播数据转发。描述控制流和数据流的运行机制,对该机制进行仿真分析。与IGMPv2嗅探方案的比较结果证明,该方案性能较高。     

组播安全及其改进的源认证

安全组播通信的主要挑战之一是源认证,而其关键是为组播通信提供可靠的安全机制。然而,现在的组播协议仅提供部分解决办法。鉴于这些原因,作者首先阐述组播通信的主要安全问题——源认证。其次,基于发送方和接收方间初始的不精确时间同步,提出了一个非常有效的方法,此方法能作到数据包一到,就允许接收方认证大部分包。     

基于MPLS的PIM-SM组播的研究与实现

研究了采用捎带技术的指定信源的PIM—SM组播在MPLS域中的实现问题，通过对现有的MPLS结构适当的修改，结合组播树的建立，就可以在MPLS域实现指定信源的PIM—SM组播，基于NS的模拟实验证明了该算法的可行性。     

树链混合组播源认证协议

源认证是组播通讯面临的一个挑战性问题,必须为大量接受者提供系统开销低、可靠性高的确认数据来源的方法.本文提出了一种有效的组播源认证协议HTC,该方案结合Hash树和多Hash链方法的优点,有效地降低了通讯开销.采用二态马尔科夫丢包模型进行了大量的仿真实验,获得了一个最优的Hash跨度组合1-2-7-11-16-20-25-30.与已有多个认证方案进行比较,说明HTC是一种有效的组播源认证方案.     

Reducing delay and enhancing DoS resistance in multicast authentication through multigrade security

Many techniques for multicast authentication employ the principle of delayed key disclosure. These methods introduce delay in authentication, employ receiver-side buffers, and are susceptible to denial-of-service (DoS) attacks. Delayed key disclosure schemes have a binary concept of authentication and do not incorporate any notion of partial trust. This paper introduces staggered timed efficient stream loss-tolerant authentication (TESLA), a method for achieving multigrade authentication in multicast scenarios that reduces the delay needed to filter forged multicast packets and, consequently, mitigates the effects of DoS attacks. Staggered TESLA involves modifications to the popular multicast authentication scheme, TESLA, by incorporating the notion of multilevel trust through the use of multiple, staggered authentication keys in creating message authentication codes (MACs) for a multicast packet. We provide guidelines for determining the appropriate buffer size, and show that the use of multiple MACs and, hence, multiple grades of authentication, allows the receiver to flush forged packets quicker than in conventional TESLA. As a result, staggered TESLA provides an advantage against DoS attacks compared to conventional TESLA. We then examine two new strategies for reducing the time needed for complete authentication. In the first strategy, the multicast source uses assurance of the trustworthiness of entities in a neighborhood of the source, in conjunction with the multigrade authentication provided by staggered TESLA. The second strategy achieves reduced delay by introducing additional key distributors in the network.