Mitigating jamming attacks in wireless broadcast systems

Wireless communications are vulnerable to signal jamming attacks. Spread spectrum mitigates these attacks by spreading normal narrowband signals over a much wider band of frequencies and forcing jammers who do not know the spreading pattern to expend much more effort to launch the attack. In broadcast systems, however, jammers can easily find out the spread pattern by compromising just a single receiver. Several group-based ideas have been proposed to deal with compromised receivers; they can tolerate up to t malicious receivers by adding 2t extra copies for each broadcast message. In this paper, we propose a novel scheme with random channel sharing. This scheme reduces the communication cost from 2t to (1 + p)t extra copies, where p determines the channel sharing probability (0 < p < 1). In addition, it does not increase the hardware complexity as it does not require a receiver to operate on multiple channels at the same time.