Author(s): P. Narasimha Rao, B. Siva Rama Krishna, Dr. Sai Satyanarayana Reddy

Wireless networks are susceptible to numerous securities threats due to the open nature of the wireless medium. Anyone with a transceiver can eavesdrop on ongoing transmissions, inject Spurious messages, or block the transmission of legitimate ones. One of the fundamental ways for degrading the network Performance is by jamming wireless transmissions. These Jamming attacks can be used for launching Denial-of-Service attacks on wireless networks. Jamming has been considered as external attack model, but if the attack is internal it cannot be solved by using methods such as spread spectrum methods. In case of internal attacks, the adversary launches jamming attacks in which it targets highly important packets. We illustrate the impact of selective jamming on the network performance by illustrating various selective attacks against the TCP protocol. A swarm based vulnerable prevention mechanism based on swarm intelligence is proposed against jamming attacks in wsn. Swarm intelligence algorithm is good in adapting according to change in network topology and traffic. Another method named channel surfing methods using attracting nodes to defend against selective jamming/dropping attacks is also proposed for enhanced security.