Advance in Electronic and Electric Engineering. ISSN 2231-1297, Volume 4, Number 4 (2014), pp. 381-388 Research India Publications http://www.ripublication.com/aeee.htm Security and Privacy Issues in Wireless Ad Hoc, Mesh, and Sensor Networks M.tech, Computer Science Engineering, Galgotias University, Plot No.2, Sector 17-A, Yamuna Expressway, Greater Noida, Gautam Buddh Nagar, U.P., India. Abstract In this paper we discuss about the improvement of security and privacy issues in wireless Ad-hoc network,wireless mesh network and wireless sensor network with the help of routing protocols, authentication and cryptographic tools. Ad hoc network is a collection of nodes that is connected through a wireless medium forming rapidly changing topologies. Attacks on ad hoc network routing protocols disrupt network performance and reliability with there solution. We briefly present the most popular protocols that follow the table-driven and the source-initiated on-demand approaches. The comparison between the proposed solutions and parameters of ad hoc network shows the performance according to secure protocols. We discuss in this paper routing protocol and challenges and also discuss authentication in ad hoc network. Keywords: Component; Wireless Network, Ad hoc Network, Security Service, Routing Protocols, Routing Authentication, Hash function and Secure Routing Protocols. 1. Introduction A wireless ad hoc network is a decentralized type of wireless network. The network is ad hoc because it does not rely on a pre existing infrastructure, such as routers in wired networks or access points in managed (infrastructure) wireless networks. Instead, each node participates in routing by forwarding data for other nodes, so the determination of which nodes forward data is made dynamically on the basis of network connectivity. In addition to the classic routing, ad hoc networks can use flooding for forwarding data. An ad hoc network typically refers to any set of networks where all devices have equal
382 status on a network and are free to associate with any other ad hoc network device in link range. Ad hoc network often refers to a mode of operation of IEEE 802.11 wireless networks. This paper provides insight into the potential applications of ad hoc networks and discusses the Technological challenges that protocol designers and network developers are faced with. These challenges include routing, service and resource discovery, Internet connectivity, Billing and security. Most recent ad hoc network research has focused on providing routing services without considering security. Wireless mesh networking has emerged as a promising technology to meet the challenges of the next generation wireless communication networks for providing flexible, adaptive, and reconfigurable architecture and offering cost-effective business solutions to the service providers [1]. The potential applications of wireless mesh networks (WMNs) are wide-ranging such as: backhaul connectivity for cellular radio access networks, high-speed wireless metropolitan area networks (WMANs), community networking, building automation, intelligent transportation system (ITS) networks, defense systems, and city-wide surveillance systems etc [2]. Although several architectures for WMNs have been proposed based on their applications [1], the most generic and widely accepted one is a three tier structure as depicted in Fig.
Security and Privacy Issues in Wireless Ad Hoc, Mesh, and Sensor Networks 383 Wireless Sensor Networks (WSN) is an emerging technology and day by day it is attracting the attention of researchers with its challenging characteristics and diversified application domain. The more researchers try to develop further cost and energy efficient computing devices and algorithms for WSN, the more challenging it becomes to fit the security of WSN into that constrained environment. However, security is crucial to the success of applying WSN. So, familiarity with the security aspects of WSN is essential before designing WSN system. This paper studies the security problems of WSN based on its resource restricted design and deployment characteristics and the security requirements for designing a secure WSN. Also, this study documents the well known attacks at the different layers of WSN and some counter measures against those attacks. Finally, this paper discusses on some defensive measures of WSN giving focus on the key management, link layer and routing security. 2. Security Requirements These factors are very important for security requirements: 2.1 Availability The term Availability means that a node should maintain its ability to provide all the designed services regardless of the security state of it [4]. This security criterion is challenged mainly during the denial-of-service attacks, in which all the nodes in the network can be the attack target and thus some selfish nodes make some of the
384 network services unavailable, such as the routing protocol or the key management service [5]. 2.2 Integrity Integrity guarantees the identity of the messages when they are transmitted. Integrity can be 7 compromised mainly in two ways [9]: Malicious altering Accidental altering A message can be removed, replayed or revised by an adversary with malicious goal, which is regarded as malicious altering; on the contrary, if the message is lost or its content is changed due to some benign failures, which may be transmission errors in communication or hardware errors such as hard disk failure, then it is categorized as accidental altering. 2.3 Confidentiality Confidentiality means that certain information is only accessible to those who have been authorized to access it. In other words, in order to maintain the confidentiality of some confidential information, we need to keep them secret from all entities that do not have the privilege to access them. 2.4 Authenticity Authenticity is essentially assurance that participants in communication are genuine and not impersonators [4]. It is necessary for the communication participants to prove their identities as what they have claimed using some techniques so as to ensure the authenticity. If there is not such an authentication mechanism, the adversary could impersonate a benign node and thus get access to confidential resources, or even propagate some fake messages to disturb the normal network operations. 2.5 Nonrepudiation Nonrepudiation ensures that the sender and the receiver of a message cannot disavow that they have ever sent or received such a message. This is useful especially when we need to discriminate if a node with some abnormal behavior is compromised or not: if a node recognizes that the message it has received is erroneous, it can then use the incorrect message as an evidence to notify other nodes that the node sending out the improper message should have been compromised. 2.6 Authorization Authorization is a process in which an entity is issued a credential, which specifies the privileges and permissions it has and cannot be falsified, by the certificate authority. Authorization is generally used to assign different access rights to different level of users. For instance, we need to ensure that network management function is only accessible by the network administrator. Therefore there should be an authorization process before the network administrator accesses the network management functions.
Security and Privacy Issues in Wireless Ad Hoc, Mesh, and Sensor Networks 385 2.7 Anonymity Anonymity means that all the information that can be used to identify the owner or the current user of the node should default be kept private and not be distributed by the node itself or the system software. This criterion is closely related to privacy preserving, in which we should try to protect the privacy of the nodes from arbitrary disclosure to any other entities. 3. Security Criteria: Summary We have discussed several main requirements that need to be achieved to ensure the security of the mobile ad hoc network. Moreover, there are some other security criteria that are more specialized and application-oriented, which include location privacy, self-stabilization and Byzantine Robustness, all of which are related to the routing protocol in the mobile ad hoc network. Having dealt with the main security criteria, we then move to the discussion on the main threats that violate the security criteria, which are generally called as attacks. 4. Attack Types in MANET There are numerous kinds of attacks in the mobile ad hoc network, almost all of which can be classified as the following two types [6]: (i) External attacks, in which the attacker aims to cause congestion, propagate fake routing information or disturb nodes from providing services. (ii) Internal attacks, in which the adversary wants to gain the normal access to the network and participate the network activities, either by some malicious impersonation to get the access to the network as a new node, or by directly compromising a current node and using it as a basis to conduct its malicious behaviors. 4.1 Attacks Against Routing Routing is one of the most important services in the network; therefore it is also one of the main targets to which attackers conduct their malicious behaviors. In the mobile ad hoc networks, attacks against routing are generally classified into two categories: attacks on routing protocols and attacks on packet forwarding/delivery [6]. Impersonating another node to spoof route message. Advertising a false route metric to misrepresent the topology. Sending a route message with wrong sequence number to suppress other legitimate route messages. Flooding Route Discover excessively as a DoS attack. Modifying a Route Reply message to inject a false route. Generating bogus Route Error to disrupt a working route. Suppressing Route Error to mislead others
386 5. Security & Privacy Ad hoc networks are intranets and they remain as intranets unless there is connectivity to the internet. Such confined Communications have already isolated attackers who are not local in the area. Note that this is not the case for wired And wireless-last hop users. Through neighbor identity authentication, a user can know if neighboring users are friendly or hostile. Information sent in ad hoc route can be protected in some way but since multiple nodes are involved, the relaying of packets has to be authenticated by recognizing the originator of the packet and the flow ID or label. 6. MANET Challenges The major challenges faced by the internet architecture can be broadly classified as: Autonomous- No centralized administration entity is available to manage the operation of the different mobile nodes. Dynamic topology- Nodes are mobile and can be connected dynamically in an arbitrary manner. Links of the network vary timely and are based on the proximity of one node to another node. Device discovery- Identifying relevant newly moved in nodes and informing about their existence need dynamic update to facilitate automatic optimal route selection. Bandwidth optimization- Wireless links have significantly lower capacity than the wired links. Limited resources -Mobile nodes rely on battery power, which is a scarce resource. Also storage capacity and power are severely limited. Scalability- Scalability can be broadly defined as whether the network is able to provide an acceptable level of service even in the presence of a large number of nodes. Limited physical security- Mobility implies higher security risks such as peerto- peer network architecture or a shared wireless medium accessible to both legitimate network users and malicious attackers. Eavesdropping, spoofing and denial-ofservice attacks should be considered. Infrastructure-less and self operated- Self healing feature demands MANET should realign itself to blanket any node moving out of its range. Poor Transmission Quality- This is an inherent problem of wireless communication caused by several error sources that result in degradation of the received signal. Ad hoc addressing- Challenges in standard addressing scheme to be implemented. Network configuration- The whole MANET infrastructure is dynamic and is the reason for dynamic connection and disconnection of the variable links. Topology maintenance- Updating information of dynamic links among nodes in MANETs is a major challenge.
Security and Privacy Issues in Wireless Ad Hoc, Mesh, and Sensor Networks 387 7. The Future Work Ad hoc networks, the most talked about term in wireless technologies, approach to be the emperor of future airs provided the vision of anytime, anywhere communications. At present, the general trend is toward mess architecture and large scale. New applications call for both bandwidth and capacity, which implies the need for a higher frequency and better spatial spectral reuse. Propagation, spectral reuse, and energy issues support a shift away from a single long wireless link (as in cellular) to a mesh of short links (as in MANET). Research on multi-hop architecture showed it a promising solution to the implementation of ad hoc networks. As the evolvement goes on, especially the need of dense deployment such as battlefield and sensor networks, the nodes in MANET will be smaller, cheaper and capable. 8. Conclusion WMNs have become an important focus area of research in the recent years owing to their great potentials in realizing numerous next-generation wireless services with stringent QoS guarantees and with high mobility support for the users. Driven by the increasing demand for rich, high-speed and bandwidth intensive content access, recent research has focused on developing high performance communication protocols for such networks, while issues like security, privacy, access control, intrusion detection, secure authentication etc. have taken the back seat. However, given the inherent vulnerabilities of the wireless medium due to its broadcast nature and multi-hop communications in WMNs, these networks are subject to a wide range of threats. This chapter has made a comprehensive presentation on the various attacks on different layers of the communication protocol stack of WMNs. While highlighting various vulnerabilities in the physical, link, network, transport and application layers, this chapter has also focused its attention on how attacks can be launched on authentication, privacy and key management protocols on WMNs. After identifying various security threats, the chapter has presented a comprehensive state of the art survey on various defense mechanisms for defending those attacks. Some of these defense mechanisms are also compared with respect to their different approaches towards security and their performance efficiencies. Finally, some of the emerging trends in research and future research issues related to security and privacy in WMNs are presented. References [1] The global mobile information systems simulation library (glomosim). http://pcs.cs.ucla.edu/projects/glomosim. [2] W. Arbaugh, N. Shankar, and Y.C. Wan. Your 802.11 wireless network has no clothes. Technical report, Dept. of Computer Science, University of Maryland, March 2001.
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