9 A Novel Approach to Hinder Jamming Attack in WSN

Wireless sensor networks (WSN) are used in many scientific and technological fields. They are used in many mission critical events nowadays in which the information/message availability, authentication and integrity is most important phenomena for the rescue operation. It is imperative that WSN should be immune to jamming attack which is a form of denial of service attack in WSN.In navigation system where information is to be spread among several motes (approximated among untrusted receivers), availability of precise information is a must. Similar is the situation in emergency alert systems. General available techniques such as frequency hopping and direct sequence techniques cannot be applied in such scenario because these depend upon secret pair wise key which is shared between the sender and the receiver before communication. This dependency has adverse effect on network because it makes the system un-scalable as well as more attack prone, e.g. when a single mote is compromised by attacker whole system is hijacked by the attacker. In this paper, we introduce un-coordinated spread spectrum techniques which do not share secret key before communication.Un coordinated spread spectrum technique can handle the unlimited numbers (most of them malicious) of receivers. Using USS techniques, the message size increases and in this way slow down the transfer speed of the message. To overcome this demerit of USS, a novel approach is presented in the paper by combining the uncoordinated spread spectrum (USS) technique with mobile agent techniques. This scheme overcomes the shortcomings of USS