Modified Belief Propagation-Based Defense against Routing Toward Primary User Attack in Cognitive Radio Networks

Current wireless networks are characterized by a static spectrum allocation policy, where governmental agencies assign wireless spectrum to license holders on a long term basis for large geographical regions ISM band has enabled the explosion of new technologies that is Wi-Fi due to this its license is free from characteristic. The widespreadadoption of Wi-Fi technology, combined with the rapid penetration of smart phonesrunning popular user services has overcrowded substantially the ISM band. Cognitive radio (CR) networks have involved many attentions newly, whilethe security issues are not yet studied fully. In this approach, propose a new and powerfulnetwork layer attack called routing-toward-primary-user (RPU) attack in Cognitive Radio networks. In this attack malicious nodes intentionally route a large amount of packets In this approach, suggest a new and powerful network layer attack called routing toward-primary-user (RPU) attack in Cognitive Radio networks. In this attack malicious nodes intentionally route a large amount of packets toward the primary users (PUs), purpose of malicious node is to cause interference to the PUs and to increase delay in thedata transmission among the secondary users. The main objective of the proposed work is to minimize the time for sendingthe data, and send the data by the path which is the longest distance from the primaryuser network. For that the pre belief value is calculated. , belief propagation used to develop a defense strategy. Here a initial rout establish from source to destination, then according to it the each node keeps a feedback of other node on the route, compute belief, exchanges of feedback in a table record. On the basis of final belief values, the source node detects the malicious path.