A Location Based Protocol for Anonymity Protection of Nodes and Routes at Low Cost

---Mobile Ad Hoc Networks (MANETs) use various anonymous routing protocols in order to provide security from outside observers. To offer high anonymity protection at low cost, An Anonymous Location Based Efficient Routing Protocol (ALERT) is proposed. ALERT dynamically partitions the network area into zones and randomly chooses the intermediate relay nodes to form a anonymous route. ALERT achieves a better routing efficiency comparable to the GPSR geographic routing protocol. Even though ALERT offers anonymity protection at low cost, it is not completely resistant to all attacks. To prevent the happening of stronger attackers, a Secure Cryptographic Based Mix zones (SCBMIX) routing is used. So to achieve anonymity protection at low cost ALERT is used and to provide stronger anonymity protection SCBMIX is used. The idea of SCBMIX is to mask the adversary from accessing the content of the messages. Thus ALERT with SCBMIX offers higher anonymity protection. Index Terms MANETs, Anonymity, routing protocol, GPSR. I.INTRODUCTION A Mobile Ad Hoc Network is an autonomous and shortlived association of group of mobile nodes that communicate with each other over wireless links. A node can directly communicate to the nodes that lie within its communication range; it uses intermediate nodes as routers. Nodes in MANETs are endangered to malicious entities that aim to tamper the data by attacking routing protocols. Anonymous routing protocols are very important in MANETs to provide secure communication by masking the node identities and prohibiting traffic analysis attacks from the attackers. Anonymity in MANETs means identifying and tracing the anonymity of sources, destinations as well as routes. Routing in MANETs Routing in a MANET generally depends up on several factors such as topology, selection of routers, location of request initiator, and specific underlying characteristics that could serve as a heuristic in finding the path quickly and efficiently. One of the major challenges in designing a routing protocol for MANETs is that a node should at least needs to know the reachability information of its neighbors for finding a packet route, while the network topology often changes in a MANET. Routing in Adhoc networks are broadly classified into Topology based or Position based approaches. Topology based routing protocols depend up on the information of the existing links in the network and use that information to perform the task of packet forwarding. They are further classified as proactive, reactive and hybrid protocols. The position-based protocols require that the physical location information of the nodes be known. Typically, each or some of the MHs determine their own position through the use of the Global Positioning System (GPS) or some other type of positioning technique. The sender normally uses a location service to determine the position of the destination node, and to incorporate it in the packet destination address field. Here, the routing process at each node is based on the destination's location available in the packet and the location of the forwarding node's neighbors. Existing anonymity routing protocols in MANETs are broadly categorized into hop-by-hop encryption and redundant traffic. In hop-by-hop encryption routing, a packet is encrypted in the transmission of two nodes en route, preventing adversaries from detecting the packet contents to interrupt the communication or identify the two communicating nodes. Hop-by-hop encryption can be classified further as onion routing and hop-by-hop authentication. Several existing protocols do not provide full anonymity protection to the source, destination and routes. For example ALARM provides only route anonymity, ZAP focuses on destination anonymity and SDDR provides the source and destination anonymity. In order to provide the high anonymity protection with low cost, Anonymous Location-based and Efficient Routing Protocol (ALERT) is proposed. The ALERT protocol divides a network field dynamically into zones and randomly chooses nodes in zones as intermediate relay nodes, which form a nontraceable anonymous route. In each routing step, a data sender partitions the network area so as to separate itself and the destination into two zones. It then randomly selects a node called as the next relay node in the other zone and uses the GPSR algorithm to send the data to the relay node. In the final step, the data is broadcasted to k nodes in the destination zone, providing k-anonymity to the destination. In addition, ALERT provides a mechanism to hide the data initiator among several senders to strengthen the anonymity protection of the source. ALERT is also elastic to intersection attacks and timing attacks. As other various anonymity routing algorithms, ALERT is not completely bulletproof to all attacks. ALERT can be applied to random way point and group mobility network models. To prevent the happening of stronger and active attackers, ALERT is mixed with SCBMIX. An unidentified zone functions as a mix zone where the nodes change their pseudonym and combine with each other. The mobile nodes do not know where the mix zone is. Mix zones [3] are created at predefined locations and to force pseudonym changes to take place within those regions. Since the location of mix-zone is fixed, the adversary can identify them and thus M.Bhavana et al, / (IJCSIT) International Journal of Computer Science and Information Technologies, Vol. 5 (5) , 2014, 6373-6378