A Secure 3-Way Routing Protocols for Intermittently Connected Mobile Ad Hoc Networks

The mobile ad hoc network may be partially connected or it may be disconnected in nature and these forms of networks are termed intermittently connected mobile ad hoc network (ICMANET). The routing in such disconnected network is commonly an arduous task. Many routing protocols have been proposed for routing in ICMANET since decades. The routing techniques in existence for ICMANET are, namely, flooding, epidemic, probabilistic, copy case, spray and wait, and so forth. These techniques achieve an effective routing with minimum latency, higher delivery ratio, lesser overhead, and so forth. Though these techniques generate effective results, in this paper, we propose novel routing algorithms grounded on agent and cryptographic techniques, namely, location dissemination service (LoDiS) routing with agent AES, A-LoDiS with agent AES routing, and B-LoDiS with agent AES routing, ensuring optimal results with respect to various network routing parameters. The algorithm along with efficient routing ensures higher degree of security. The security level is cited testing with respect to possibility of malicious nodes into the network. This paper also aids, with the comparative results of proposed algorithms, for secure routing in ICMANET

A mobile agent and message ferry mechanism based routing for delay tolerant network

Delay Tolerant Network (DTN) is a class of networks characterized by long delays, frequent disconnections and partitioning of communication paths between network nodes. Due to the frequent disconnection and network partitioning, the overall performance of the network will be deteriorated sharply. The problem is how to make the network fairly connected to optimize data routing and enhance the performance of a network. The aim of this study is to improve the performance of DTN by minimizing end-to-end delivery time and increasing message delivery ratio. Therefore, this research tackles the problem of intermittent connectivity and network partitioning by introducing Agents and Ferry Mechanism based Routing (AFMR). The AFMR comprises of two stages by applying two schemes: mobile agents and ferry mechanism. The agents' scheme is proposed to deal with intermittent connectivity and network partitioning by collecting the basic information about network connection such as signal strength, nodes position in the network and distance to the destination nodes to minimize end-to-end delivery time. The second stage is to increase the message delivery ratio by moving the nodes towards the path with available network connectivity based on agents' feedback. The AFMR is evaluated through simulations and the results are compared with those of Epidemic, PRoPHET and Message Ferry (MF). The findings demonstrate that AFMR is superior to all three, with respect to the average end-to-end delivery time, message delivery ratio, network load and message drop ratio, which are regarded as extremely important metrics for the evaluation of DTN routing protocols. The AFMR achieves improved network performance in terms of end-to-end delivery time (56.3%); enhanced message delivery ratio (60.0%); mitigation of message drop (63.5%) and reduced network load (26.1 %). The contributions of this thesis are to enhance the performance of DTN by significantly overcoming the intermittent connectivity and network partitioning problems in the network

Energy-Efficient Routing In Sparse Networks

Routing in sparse networks results in relatively long packet delivery delays and is unreliable. Thus, sparse networks are not an appropriate networking solutions for applications in which delay delivery is of critical importance. However, some applications can tolerate substantial amount of delay. Networks which can support communication for such applications are referred to as the Delay-Tolerant Networks (DTNs). Epidemic Routing Protocol (ERP) has been proposed and widely used for routing in DTNs. ERP is based on the concept of packet flooding - a node that carries a packet transmits (i.e., replicates) the packet to every node that it encounters. Thus, the numbers of copies of the packet rapidly increases. This type of routing results in the shortest possible packet delivery delay and in high packet delivery probability. However, these results come with strict assumptions that the network nodes have sufficiently large amount of energy and storage. In case where the network sequentially routes multiple packets, increasing the number of copies of the packet has its disadvantages. First is the excessive amount of energy used for transmissions. When nodes have limited amount of battery energy, increased number of copies eventually results in faster depletion of the batteries of the network nodes, reduction in the number of active nodes, and in reduced network lifetime. Second is the amount of memory used for packet storage. A node is likely to receive many different packets which will pile up the memory before the node encounters the sink. When its memory is full, the node should either remove a packet from its memory, or not receive another packet. Either way, this results in less packet copies and decrease of packet delivery probability. This study analyzes the ERP for two different cases and shows how to overcome the disadvantages by modifying the ERP. In case when the nodes have limited battery energy, minimizing and equalizing the energy expenditure at the nodes efficiently increases the network lifetime. In case when the nodes have limited storage, using linear combinations of multiple packets increase the packet delivery probability without any major cost of energy or storage

Reliable Communications over Heterogeneous Wireless Networks

The recent years have seen an enormous advance in wireless communication technology and co-existence of various types of wireless networks, which requires effective inter-networking among the heterogeneous wireless networks in order to support user roaming over the networks while maintaining the connectivity. One of main challenges to achieve the connectivity over heterogeneous wireless networks is potential intermittent connections caused by user roaming. The issue is how to maintain the connection as the user roams and how to ensure service quality in the presence of a long disconnection period. In this dissertation, we apply the delay tolerant network (DTN) framework to heterogeneous terrestrial wireless networks, and propose a system architecture to achieve the connectivity in the presence of excessive long delays and intermittent paths. We study several possible approaches, discuss the applicability of each of the approaches and propose the super node architecture. To demonstrate the effectiveness of the proposed super node architecture, we give a simulation study that compares the system performance under the super node architecture and under the epidemic based architecture. Within the proposed architecture that employs the idea of super nodes, we further study how to effectively route a message over access networks. We present a new routing technique for mobile ad-hoc networks (MANETs) based on the DTN system architecture. We introduce the concept of virtual network topology and redefine the dominating-set based routing for the challenged network environment under consideration. In addition, we propose a time based methodology to predict the probability of future contacts between node pairs to construct the virtual network topology. We present a simulation study that demonstrates the effectiveness of the proposed routing approach as compared with the epidemic routing, and that the time based technique for predicting the future contacts gives better performance compared with that using the number of previous contacts. We further extend the dominating set routing technique through analyzing the underlying node mobility model. We shed some light on how using node mobility model can improve contact probability estimation. Based on our findings we propose a new algorithm that improves the routing performance by minimizing the selected dominating set size. Information security challenges in the super node architecture are introduced. We further address two main security challenges: The first is how to prevent unauthorized nodes from using the network resources, and the second is how to achieve end-to-end secure message exchange over the network. Our proposed solutions are based on asymmetric key cryptography techniques. Moreover, we introduce a new idea of separating the problem of source authentication from the problem of message authorization. We propose a new technique that employs the one-way key chain to use symmetric key cryptographic techniques to address the problems under consideration

Hybrid routing in delay tolerant networks

This work addresses the integration of today\\u27s infrastructure-based networks with infrastructure-less networks. The resulting Hybrid Routing System allows for communication over both network types and can help to overcome cost, communication, and overload problems. Mobility aspect resulting from infrastructure-less networks are analyzed and analytical models developed. For development and deployment of the Hybrid Routing System an overlay-based framework is presented

Hybrid Routing in Delay Tolerant Networks

This work addresses the integration of today\u27s infrastructure-based networks with infrastructure-less networks. The resulting Hybrid Routing System allows for communication over both network types and can help to overcome cost, communication, and overload problems. Mobility aspect resulting from infrastructure-less networks are analyzed and analytical models developed. For development and deployment of the Hybrid Routing System an overlay-based framework is presented

Resource Efficient Urban Delay/disruptive Tolerant Networks

Ph.DDOCTOR OF PHILOSOPH

Artificial immune system based security algorithm for mobile ad hoc networks

Securing Mobile Ad hoc Networks (MANET) that are a collection of mobile, decentralized, and self-organized nodes is a challenging task. The most fundamental aspect of a MANET is its lack of infrastructure, and most design issues and challenges stem from this characteristic. The lack of a centralized control mechanism brings added difficulty in fault detection and correction. The dynamically changing nature of mobile nodes causes the formation of an unpredictable topology. This varying topology causes frequent traffic routing changes, network partitioning and packet losses. The various attacks that can be carried out on MANETs challenge the security capabilities of the mobile wireless network in which nodes can join, leave and move dynamically. The Human Immune System (HIS) provides a foundation upon which Artificial Immune algorithms are based. The algorithms can be used to secure both host-based and network-based systems. However, it is not only important to utilize the HIS during the development of Artificial Immune System (AIS) based algorithms as much as it is important to introduce an algorithm with high performance. Therefore, creating a balance between utilizing HIS and AIS-based intrusion detection algorithms is a crucial issue that is important to investigate. The immune system is a key to the defence of a host against foreign objects or pathogens. Proper functioning of the immune system is necessary to maintain host homeostasis. The cells that play a fundamental role in this defence process are known as Dendritic Cells (DC). The AIS based Dendritic Cell Algorithm is widely known for its large number of applications and well established in the literature. The dynamic, distributed topology of a MANET provides many challenges, including decentralized infrastructure wherein each node can act as a host, router and relay for traffic. MANETs are a suitable solution for distributed regional, military and emergency networks. MANETs do not utilize fixed infrastructure except where a connection to a carrier network is required, and MANET nodes provide the transmission capability to receive, transmit and route traffic from a sender node to the destination node. In the HIS, cells can distinguish between a range of issues including foreign body attacks as well as cellular senescence. The primary purpose of this research is to improve the security of MANET using the AIS framework. This research presents a new defence approach using AIS which mimics the strategy of the HIS combined with Danger Theory. The proposed framework is known as the Artificial Immune System based Security Algorithm (AISBA). This research also modelled participating nodes as a DC and proposed various signals to indicate the MANET communications state. Two trust models were introduced based on AIS signals and effective communication. The trust models proposed in this research helped to distinguish between a “good node” as well as a “selfish node”. A new MANET security attack was identified titled the Packet Storage Time attack wherein the attacker node modifies its queue time to make the packets stay longer than necessary and then circulates stale packets in the network. This attack is detected using the proposed AISBA. This research, performed extensive simulations with results to support the effectiveness of the proposed framework, and statistical analysis was done which showed the false positive and false negative probability falls below 5%. Finally, two variations of the AISBA were proposed and investigated, including the Grudger based Artificial Immune System Algorithm - to stimulate selfish nodes to cooperate for the benefit of the MANET and Pain reduction based Artificial Immune System Algorithm - to model Pain analogous to HIS