一种适用于Ad Hoc网络的密钥管理方案

为了Ad Hoc网络能够更好的应用和发展,必须有效的解决其安全隐患,由于Ad Hoc网络中不存在可信任的中心,其密钥管理就显得尤为重要.文中提出了一种改进的Ad Hoc网络密钥管理方案.改进后的方案采用可验证的秘密共享、公钥加密和随机数相结合的技术.分析结果表明,该方案进一步提高了安全性,同时降低了计算量.     

Hexagonal Clustered Trust Based Distributed Group Key Agreement Scheme in Mobile Ad Hoc Networks

Secure and efficient group communication among mobile nodes is one of the significant aspects in mobile ad hoc networks (MANETs). The group key management (GKM) is a well established cryptographic technique to authorise and to maintain group key in a multicast communication, through secured channels. In a secure group communication, a one-time session key is required to be shared between the participants by using distributed group key agreement (GKA) schemes. Due to the resource constraints of ad hoc networks, the security protocols should be communication efficient with less overhead as possible. The GKM solutions from various researches lacks in considering the mobility features of ad hoc networks. In this paper, we propose a hexagonal clustered one round distributed group key agreement scheme with trust (HT-DGKA) in a public key infrastructure based MANET environment. The proposed HT-DGKA scheme guarantees an access control with key authentication and secrecy. The performance of HT-DGKA is evaluated by simulation analysis in terms of key agreement time and overhead for different number of nodes. Simulation results reveal that the proposed scheme guarantees better performance to secure mobile ad hoc network. It is demonstrated that the proposed scheme possesses a maximum of 2250 ms of key agreement time for the higher node velocity of 25 m/s and lower key agreement overhead. Also, the HT-DGKA scheme outperforms the existing schemes in terms of successful message rate, packet delivery ratio, level of security, computation complexity, number of round, number of exponentiations and number of message sent and received that contribute to the network performance.

     

移动Ad hoc网络中的密钥管理

首先阐述了移动adhoc网络中密钥管理的重要性,接着探讨了几种密钥管理的方法,包括局部分布式认证授权中心、完全分布式认证授权中心、自发证书、安全Pebblenets、指示性标志、基于口令验证的密钥交换等,并对这些方法进行了较完整的概括总结和深入的比较分析,最后提出了一些研究移动adhoc网络中密钥管理方法所必须注意的问题。     

基于虚拟骨干网技术的自组网络移动IP方案

在自组网络中，虚拟骨干网技术的基本思想是数据包的分发控制由构成虚拟骨干网的节点负责，从而能够有效地提高无线自组网络的链路利用率，并能更好地适应快速网络拓扑变化。提出了一种基于虚拟骨干网技术的移动IP方案，它结合虚拟骨干网技术和移动IP的优势，具有易实现性和较好的性能。     

Spontaneous Group Management in Mobile Ad Hoc Networks

This paper deals with the problem of Location Management in mobile ad hoc networks where users are organized in groups. In the following this type of systems are referred to as Mobile Ad hoc Networks for Group Operations (MANGO). This paper proposes a framework for location management which exploits the trend of mobile users to spontaneously form groups in MANGOs. The management procedures required to support such spontaneous groups, which are by nature dynamic, are introduced as well. The proposed spontaneous group management is based on a hierarchical location database architecture and the concept of Group Leader, which is a terminal responsible for the location update of a group of terminals. Objective of the proposed framework is minimizing the burden on location databases and, at the same time, the signaling issued by terminals. In this paper, distributed operations required to support the whole framework are properly introduced and described. Simulation experiments have been run in order to assess the proposed scheme. Performance results show that the introduced methodology allows reduced signaling and location updating.     

一种基于冗余路径的自组网密钥管理方案研究

基于部分分布式门限机制的密钥管理方案能提供高的安全性,但认证成功率较低,可扩展性差;基于证书链的密钥管理方案适合自组网的特点,但不能满足高安全要求的应用环境.在Hubaux证书链方案的基础上,文中提出了基于冗余路径的自组网密钥管理方案,该方案提高了系统的安全性,防止了不诚实节点的欺骗攻击;仿真结果表明,通过增加本地节点存储的证书数量,可以达到较高的认证成功率,满足自组网应用的高安全要求.     

Ad Hoc网络中一种基于救赎机制的信任模型

在Ad Hoc网络中,节点由于自私等恶意原因以及链路错误导致拒绝转发数据,需要采用适当的机制来提高网络的转发性能。提出一种Ad Hoc网络中的信任模型来激励节点间的协作,在此信任模型中,每个节点通过直接监控和其它节点的推荐监控信息共同完成对邻居节点的信任评价,并维护所有邻居节点的信任值,同时在信任值更新和重建中引入信任值衰退和信任救赎机制来体现模型的健壮性。实验表明该信任模型中的信任救赎机制能提高网络可用性,且该模型有效抑制了恶意节点的行为。     

一种新的野战Ad Hoc网络分层密钥管理方案

野战军事网络极易受到各种攻击和破坏,有效的密钥管理是实现安全通信的关键。该文提出了一种分层密钥管理方案,具有可靠性、高效性、管理方便、易于实现的特点。     

Ad Hoc网络可靠性评估

针对一种特殊的通信网Ad Hoc网络,提出了一种可靠性评估算法,首先根据物理拓扑抽象出Ad Hoc网络模型,并充分分析Ad Hoc网络特点确定失效判据,依据失效判据进行可靠性建模,选择合适的可靠性模型。将Ad Hoc网络模型划分为逻辑上的一个个子区域,采用层次分析法确定各个子区域的权重系数,在各子区域内,利用最小定点割集确定Ad Hoc网络中的重要节点,同时根据生成树算法确定重要节点的权重系数,从而可以计算出Ad Hoc网络的可靠度。最后通过实例说明某Ad Hoc网络的可靠性评估。     

RandomCast: An Energy-Efficient Communication Scheme for Mobile Ad Hoc Networks

In mobile ad hoc networks (MANETs), every node overhears every data transmission occurring in its vicinity and thus, consumes energy unnecessarily. However, since some MANET routing protocols such as Dynamic Source Routing (DSR) collect route information via overhearing, they would suffer if they are used in combination with 802.11 PSM. Allowing no overhearing may critically deteriorate the performance of the underlying routing protocol, while unconditional overhearing may offset the advantage of using PSM. This paper proposes a new communication mechanism, called RandomCast, via which a sender can specify the desired level of overhearing, making a prudent balance between energy and routing performance. In addition, it reduces redundant rebroadcasts for a broadcast packet, and thus, saves more energy. Extensive simulation using ns-2 shows that RandomCast is highly energy-efficient compared to conventional 802.11 as well as 802.11 PSM-based schemes, in terms of total energy consumption, energy goodput, and energy balance.     

移动Ad Hoc网络中的安全问题

移动自组网(Mobile Ad HoC Network)是一种无基础设施的无线网络由于它具有开放的媒质、分布式的合作、动态的拓扑结构和受限的网络能力等特点,所以特别容易受到攻击.为此文章结合移动Ad Hoc网络的特点分析了移动Ad Hoc网络面临的安全威胁,并对移动Ad Hoc网络的安全路由和安全报文传送问题进行了详细讨论.     

Mobility Aware Clustering Scheme with Bayesian-Evidence Trust Management for Public Key Infrastructure in Ad Hoc Networks

Wireless Personal Communications - The autonomous nodes in Mobile Ad Hoc Networks (MANETs) are vulnerable to attacks ranging from passive to active, due to the dynamic mobility paradigm. Earlier,...     

基于HELLO机制的MANET与Internet高效互联

文章提出一种基于AODV HELLO机制的移动自组网与Internet互联方案。该方案直接在AODV HELLO分组中包含网关信息以及相邻节点列表．从而在无需引入额外控制分组的前提下进行网关发现并同时避免了在路由计算中引入单向链路。结合使用高效的半隧道转发机制，使得互联性能得到显著提升而开销合理，基于NS2的仿真结果显示了其有效性。     

A Mutual Exclusion Algorithm for Ad Hoc Mobile Networks

A fault-tolerant distributed mutual exclusion algorithm that adjusts to node mobility is presented, along with proof of correctness and simulation results. The algorithm requires nodes to communicate with only their current neighbors, making it well-suited to the ad hoc environment. Experimental results indicate that adaptation to mobility can improve performance over that of similar non-adaptive algorithms when nodes are mobile.     

A Dominating-Set-Based Routing Scheme in Ad Hoc Wireless Networks

Efficient routing among a set of mobile hosts (also called nodes) is one of the most important functions in ad hoc wireless networks. Routing based on a connected dominating set is a promising approach, where the searching space for a route is reduced to nodes in the set. A set is dominating if all the nodes in the system are either in the set or neighbors of nodes in the set. In this paper, we propose a simple and efficient distributed algorithm for calculating connected dominating set in ad hoc wireless networks, where connections of nodes are determined by their geographical distances. We also propose an update/recalculation algorithm for the connected dominating set when the topology of the ad hoc wireless network changes dynamically. Our simulation results show that the proposed approach outperforms a classical algorithm in terms of finding a small connected dominating set and doing so quickly. Our approach can be potentially used in designing efficient routing algorithms based on a connected dominating set.     

A Hybrid Collision Avoidance Scheme for Ad Hoc Networks

A novel hybrid collision avoidance scheme that combines both sender-initiated and receiver-initiated collision-avoidance handshake is proposed for multi-hop ad hoc networks. The new scheme is compatible with the popular IEEE 802.11 MAC protocol and involves only some additional queue management and book-keeping work. Simulations of both UDP- and TCP-based applications are conducted with the IEEE 802.11 MAC protocol, a measurement-based fair scheme and the new scheme. It is shown that the new scheme can alleviate the fairness problem with almost no degradation in throughput. More importantly, it is shown that without explicit information exchange among nodes, the fairness problem cannot be solved conclusively if reasonable throughput is to be maintained. Hence it calls for further work to integrate the new collision avoidance scheme with other schemes that approximate fair queueing and use more contention information in channel access to achieve some QoS assurances in ad hoc networks.     

一种实用的适用于移动自组织网络的认证协议

与传统网络相比，自组织网络本身存在许多系统脆弱性．使得传统网络安全机制不再适用于自组织网络。文章对传统PKI作必要改进，定义了适用于自组织网络的的公钥基础设施AH-PKI．并设计了一种基于AH-PKI的认证协议。     

Ad hoc网络中的路由技术

Ad hoc网络是一些移动节点组成一个多跳的临时性无线自治系统，这种新型的通信网络具有动态变化的拓扑结构和分布控制的网络机制。文中针对Ad hoc网络作了简单的介绍并重点介绍了针对Ad hoc网络特性而提出的路由协议。     

Internet Connectivity for Ad Hoc Mobile Networks

The growing deployment rate of wireless LANs indicates that wireless networking is rapidly becoming a prevalent form of communication. As users become more accustomed to the use of mobile devices, they increasingly want the additional benefit of roaming. The Mobile IP protocol has been developed as a solution for allowing users to roam outside of their home networks while still retaining network connectivity. The problem with this solution, however, is that the deployment of foreign agents is expensive because their coverage areas are limited due to fading and interference. To reduce the number of foreign agents needed while still maintaining the same coverage, ad hoc network functionality can cooperate with Mobile IP such that multihop routes between mobile nodes and foreign agents can be utilized. In this work, we present a method for enabling the cooperation of Mobile IP and the Ad hoc On-Demand Distance Vector (AODV) routing protocol, such that mobile nodes that are not within direct transmission range of a foreign agent can still obtain Internet connectivity. In addition, we describe how duplicate address detection can be used in these networks to obtain a unique co-located care-of address when a foreign agent is not available.