Security in Pervasive Computing

With the rapid development of information technology and the increasing application of UAV in various fields, the security problems of unmanned aerial vehicle (UAV) communication network have become increasingly prominent. It has become an important scientific challenge to design a routing protocol that can provide efficient and reliable node to node packet transmission. In this paper, an efficient Digital Signature algorithm based on the elliptic curve cryptosystem is applied to routing protocol, and an improved security method suitable for on-demand routing protocol is proposed. The UAV communication network was simulated through the NS2 simulation platform, and the execution efficiency and safety of the improved routing protocol were analyzed. In the simulation experiment, the routing protocols of ad-hoc on demand distance vector (AODV), security ad-hoc on demand distance vector (SAODV), and improved security ad-hoc on demand distance vector (ISAODV) are compared in terms of the performance indicators of packet delivery rate, throughput, and end-to-end delay under normal conditions and when attacked by malicious nodes. The simulation results show that the improved routing protocol can effectively improve the security of the UAV communication network.

Mobile ad hoc network (MANET) is lacking infrastructure support, so nodes of MANET are vulnerable to attacks. Denial of Service attacks (DOS) makes network inaccessible to users. Black hole attack is a type of DOS attack, in which mischievous node claims that it has a route towards the destination node. Ad Hoc on Demand Distance Vector (AODV) routing protocol is affected by Black hole attack. The proposed solution is based on first Route Reply (RREP) caching mechanism in AODV protocol. Simulation results show performance improvement in routing protocol.

Mobile Ad Hoc Networks (MANETs) pose challenges in terms of power control, due to their fixed transmission power, the mobility of nodes and a constantly changing topology. High levels of power are needed in wireless networks, particularly for routing. In order to address this problem, power aware routing protocols have been proposed, with the aim of maximising the lifetime of the network. This paper presents an enhancement to the Ad Hoc On Demand Distance Vector (AODV) protocol, by reducing transmission power, when a large number of other radios are within range. This protocol, called DP-AODV (Dynamic Power AODV) combines the hello packet mechanism and the power control mechanism in order to reduce interference between nodes and increase the throughput in the network, thus reducing the overall power consumption. A performance evaluation of this enhanced protocol is carried out in comparison with three standard routing protocols, Ad Hoc On Demand Distance Vector (AODV), Ad Hoc On Demand Multipath Distance Vector (AOMDV) and Dynamic Source Routing (DSR), using network simulator 2 (NS2). Keywords-MANET; Dynamic Power; Density; Mobility; Interference.

An innovative method is proposed to analyze the nodes and its packets, in order to identify the malicious nodes which are created by the single or black hole attacks in the mobile ad hoc networks, by timeout period analysis. Timeout period acts as an imperative function to avoid the false alarms and predicts the misbehaving nodes accurately. The proposed method is dependent on the ad hoc on-demand distance vector (AODV) routing protocol and IEEE 802.11 MAC protocol. This paper proposed modified AODV with timeout period analysis for each transmitted packets from the nodes with queuing analysis for computing the average, minimum and maximum delay of packet transmission. The existing AODV protocol was modified to adopt the timeout period analysis, detect the malicious nodes which are to be changed as single or cooperative black hole nodes and remove the nodes from the network. The network simulator is used to simulate the modified AODV protocol to analyze the performance of the obtained results and correlate the results.

Ad Hoc Routing with Distributed Ordered Sequences

Mobile ad hoc networks (MANET) are collections of self-organizing mobile nodes with dynamic topologies and have no fixed infrastructure. MANET do not have centralized administration, here nodes act as both host as well as router and communicate by forwarding packets for each other in multi hop way, because of the fundamental characteristics like, the open medium, dynamic network topology, lack of centralized monitoring and management these networks are particularly vulnerable to various types of attacks. One of the routing protocol being used for wireless network is Ad hoc on demand distance vector (AODV). Black hole is one of the attack that is launched on AODV. In this attack, the attacker claims the shortest route to the destination and hinders the communication by dropping all the packets. In this paper, a new solution against the Black Hole attack is proposed. This paper demonstrates a timer based detection approach for identifying black hole node. In network layer we proposed a Timer based method to overhear the next node action. The simulation results using EXata-Cyber shows that in a dynamic network most of the malicious nodes can be detected and that results in an improved packet delivery ratio.

Mobile Ad-hoc Networks (MANETs) features such as open medium, dynamic topology, lack of centralised management and lack of infrastructure expose them to a number of security attacks. Black hole attack is one type of attack that is more common in MANET reactive routing protocols such as Ad-hoc On-demand Distance Vector (AODV) and Dynamic Source Routing (DSR). Black hole attack takes advantage of route discovery process in reactive routing protocols. In this type of attack, a malicious node misleads other nodes in the network by pretending to have the shortest and updated route to a target node whose packets it wants to interrupt. It then redirects all packets destined to a target node to itself and discards them instead of forwarding. This paper analyses the performance of AODV and DSR when attacked by black hole, by varying the mobility of the nodes in the network. The analysis is carried out by simulating scenarios of AODV based MANET and DSR based MANET using Network Simulator 2 (NS-2) and introducing the black hole attack in each of the scenarios. The different scenarios are generated by changing the mobility of the nodes. The performance metrics that are used to do the analysis are throughput, packet delivery ratio and end-to-end delay. The simulation results show that the performance of both AODV and DSR degrades in the presence of black hole attack. Throughput and packet delivery ratio decrease when the network is attacked by black hole because the malicious node absorbs or discards some of the packets. End-to-end delay is also reduced in the presence of a black hole attack because a malicious node pretends to have a valid route to destination without checking the routing table, and therefore shortens the route discovery process. The results also show that throughput decreases slightly when mobility of the nodes is increased in the network. The increase in the speed of the nodes decreases both end-to-end delay and packet delivery ratio.

<p class="western" style="margin-top: 0.21cm; margin-bottom: 0cm; line-height: 100%;" lang="en-US" align="justify"><span>Mo</span><strong><span>b</span></strong><span>ile Ad-Hoc Networks (MANETs) are supreme ruler and demoralization wireless scheme. MANETs are infrastructure less i.e. their structure is not fixed, and the nodes be able to move about and can leave the network whenever they want. The nodes are to perform as more over router and host. In MANETs, the node can be in contact with every node as their configuration is not fixed and the nodes starts transmitting the packets to each other for the establishment of the connection. To hitch the link, the nodes make use of some routing protocols like Ad-Hoc On Demand Distance Vector (AODV), Dynamic Source Routing (DSR), and DestinationSequenced Distance Vector (DSDV). Security in MANET is the key matter meant for the fundamental utility of network. There are many attacks caused in MANET. Blackhole attack is one that occurs in MANET. A Black hole attack is an attack where the node, which is malicious advertise itself as having the optimal route to the destination and drops all the packets instead of forwarding further to the destination. Here, we have shown the blackhole attack in AODV and DSR. Through simulation we evaluate the performance of the two above protocols under blackhole attack.</span></p>

This paper evaluates and compares mobile ad hoc network (MANET) routing protocols for wireless sensor network (WSN). It focuses and compares the performance analysis based on Quality of Service (QoS) factors on the throughput and delay between Ad Hoc on Demand Distance Vector (AODV) and Temporary Ordered Routing Algorithm (TORA) protocols for mesh network with a single source. Ad Hoc on Demand Distance Vector is a reactive protocol and Temporary Ordered Routing Algorithm is on-demand reactive protocol which is the hybrid protocol. Previous research did shown that AODV is better than TORA for a larger nodes that is more than 30 nodes an some says that TORA is better for smaller nodes environment. In wireless ad hoc network, the nodes must be able to interconnect each other to establish the link or connection from source to the destination. The results show that AODV outperformed TORA in the throughput but AODV had higher delay than TORA. After the analysis has been done, this paper shows that AODV outperforms TORA in the wireless sensor network only with a single source and destination which less than 30 nodes in a network.

An ad hoc network is a collection of mobile devices that communicate in a self-organized way using wireless network interfaces without neither centralized administration nor fixed infrastructure. In such a network, nodes must cooperate with each other so as to extend their transmission range to reach distant nodes. This cooperation requires a specific ad hoc routing protocol to establish and maintain routes between nodes. Ad hoc routing protocols are based on mutual trust between collaborating nodes and suppose a correct behavior. As a result, these networks are particularly vulnerable to various security threats. , and therefore, security is a more significant issue than infrastructure-based wireless networks. In this paper, we present security analysis of the Ad hoc On-demand Distance Vector (AODV) routing protocol to identify all possible security threats that can target its algorithm, such as resources depletion, blackhole, wormhole and rushing attacks. Keywords—MANET; AODV; security attacks; malicious node;

MANET is vulnerable to most of the security threats and we proposed a combined approach which is used to detect both the black hole and worm hole attack. We also carried out black hole and worm hole attack on MANET using Ad hoc On Demand Distance Vector (AODV) routing protocol and analyzed the performance parameters like Throughput, Packet Delivery Ratio(PDR) and Normalized Routing Load (NRL). After implementation of proposed technique, we found that the parameters for Quality of Services (QoS) in MANET improved significantly as compare to conventional techniques.

Ad hoc networks, formed by multiple wireless communication devices without any connection to wired or intermediary devices such as by access points, are widely used in various situations to construct flexible networks that are not restricted by communication facilities. Ad hoc networks can rarely use existing infrastructure, and no authentication infrastructure is included in these networks as a trusted third party. Hence, distinguishing between ordinary and malicious terminals can be challenging. As a result, black hole attacks are among the most serious security threats to Ad hoc On-demand Distance Vector (AODV) routing, which is one of the most popular routing protocols in mobile ad hoc networks. In this study, we propose a defense method against black hole attacks in which malicious nodes are actively detected to prevent attacks. We applied the proposed method to a network containing nodes engaging in black hole attacks, confirming that the network’s performance is dramatically improved compared to a network without the proposed method.

Recently, special types of routing protocols are designed for sensor networks. Almost all of these routing protocols have considered the energy efficiency as the ultimate objective in order to maximize the lifetime of the whole network. The different types of routing protocols available in WSN are data centric, hierarchical, and location-based and on demand routing protocols. Low-Energy Adaptive Clustering Hierarchy (LEACH) protocol is one of the best hierarchical clustering protocols with probabilistic model to manage the energy consumption of WSN. However, LEACH uses global information without considering the local information i.e. the residual energy of each node for CH election process. Hence, Deterministic Energy-efficient Clustering protocol (DEC), a deterministic model is developed by using clustering scheme to manage and organize the WSN with mobile scenario. This protocol promises a better election of cluster-heads based on residual energy information and it is more energy efficient than LEACH protocols. Ad hoc on demand Distance Vector (AODV) is another routing protocol used in sensor network to support mobility. AODV is also on demand routing protocol. However, AODV do not provide multipath loop free and has link disjoint path. Hence, Ad hoc On-demand Multipath Distance Vector (AOMDV) is developed for WSN to guarantee loop freedom and disjointness of alternate paths. Frequent route discovery and route failure is occurred in AOMDV protocols due to the involvement of repeated mobile nodes without checking the energy levels of those nodes for packet transmission. To reduce the route failures occurred by the usage of nodes with reduced energy, energy aware ad hoc on-demand multipath distance vector routing protocol (E-AOMDV) is developed by incorporating energy aware concept in AOMDV protocol to increase the network performance. In this paper, the performance analysis namely residual energy of DEC protocol is examined for various packet length and nodes. Delivery ratio analysis of EAOMDV protocol is also done in this paper for various simulation times and nodes. The simulation results shows that DEC has better performance than LEACH and also E-AOMDV has better performance than AOMDV.

With the onset of multimedia applications, Quality of Service (QoS) in 802.11-based wireless ad hoc networks has been an essential area to look into. Standard wireless protocols such as IEEE 802.11b and IEEE 802.11e have been deemed unsuitable for multimedia traffic transmission in an ad hoc (multihop) network environment due to the unique network characteristics. As an ad hoc network is infrastructureless and distributed in nature, it gives rise to several challenges in QoS provisioning. In this thesis, we focus on the research of three key areas on QoS in ad hoc networks namely, buffer management in the medium access control (MAC) layer, cross-layer design and flow admission control. Firstly, we study MAC layer buffer management in the IEEE 802.11e protocol. The IEEE 802.11e MAC protocol provides QoS for multimedia traffic by probabilistic priority queueing. Ad hoc networks tend to generate a large volume of network control packets for route maintenance and these control packets are typically queued in the highest priority queue. As a result, higher priority control traffic is always being served, consuming most of the bandwidth and results in poor network performance for data traffic. We examine this problem and propose a dynamic buffer management scheme to mitigate it. By setting different threshold levels in different priority queues, we allow lower priority data traffic to be served when the higher priority control traffic is deemed to be excessive. Simulation of our proposed scheme has shown that our approach yielded better network performance compared to the standard protocol in terms of packet delivery ratio and average delay. Secondly, we study the cross-layer interaction between the MAC and Network layers to identify its impact on QoS. We select the IEEE 802.11e MAC protocol and Ad-hoc On Demand Distance Vector (AODV) routing protocol in our study since they are standardized protocols for wireless networks. In IEEE 802.11e MAC protocol, lower priority traffic has a higher probability of being blocked. Hence, the MAC layer will inform the Network layer of a broken link through the link notification function. In this case, AODV will re-route the paths that traverse this link. As a result, higher priority traffic which shares the same link as the lower priority traffic will undergo the same re-routing procedures. We termed this phenomenon path correlation effect. Under high traffic load, the path correlation effect will be more intense and hence degrade the QoS of higher priority traffic. To break the path correlation effect, we propose a cross-layer design called the Bundled Virtual Circuit (BVC). Our proposed BVC scheme not only addresses the path correlation issues, but also provides priority treatment from the Network layer to the MAC layer. Through our simulations, our proposed cross-layer design approach is proven to provide better network performance than the 802.11e/AODV protocols in terms of packet delivery ratio and delay. Finally, we examine flow admission control at the routing layer in ad hoc networks. Standard routing protocols such as AODV performs routing on a shortest path basis. In the presence of multiple routes, hotspots are likely to form among the intermediate nodes and thus lead to network congestion. In addition, existing routes are not well-protected from the introduction of new routes. We propose a flow admission control algorithm to be used with AODV. Our algorithm allows routes to be created through available bandwidth and congestion estimation. During the route discovery phase, each node will be gauged on its estimated available bandwidth and its backlog of packets in the MAC buffer. If a node does not have sufficient bandwidth, or has too many backlogged packets compared to the requested flow rate, it will not participate in the route discovery process. From simulations, our new scheme is able to provide better network performance than the standard AODV protocol in terms of delay. Our work in this thesis focuses on QoS provisioning in ad hoc networks from the MAC and network layer perspectives. By studying the network characteristics and protocols’ behavior, we investigate the various problems of providing QoS in an ad hoc network environment and propose three different schemes to improve the QoS provisioning at the MAC and network layers. We believe that our work is able to provide some insights to the research area on QoS in ad hoc networks.

The two ad-hoc routing protocols, Ad-hoc On demand Distance Vector (AODV) and Dynamic Source Routing (DSR) suffer a number of shortcomings. The main issues are longer path set up time in case of link failures, scalability problem because of routing overhead and etc. A combination of the two routing protocols called DOA (DSR over AODV) is used to overcome these issues. DOA is usually implemented using a model called Way Point Routing model in which the problem of position estimation errors occurs. This work enhances DOA with a new algorithm called Exponential Weighted Moving Average (EWMA) for on-line updating of nodal contact probability to minimize the possibilities of position estimation errors. In this work, new packet called Delay to Send (DTS) packets instead of NACK packets has been used in addition to RTS and CTS packets. Here DTS packets are to recover the delayed data within a certain time period instead of dropping the packet after final retransmission in case of delay due to unexpected traffic in packet delivery. A Simulation analysis is carried out to analyze the performance of DOA with EWMA compared to AODV and DSR. It proves that DOA with EWMA reduces the routing overhead by 80% and scalability problem that occurred in AODV and DSR.