Unconditional Security Wireless Communication
Wyner, Csiszar and Korner developed the concept of the wiretap channel for wired links. In a wiretap channel, the eavesdropper is assumed to receive messages transmitted by the sender over a channel that is noisier than the legitimate receiver’s channel. Under this condition, it is possible to establish perfectly secure source–destination link without relying on secret keys. Unfortunately, it may often be impossible to guarantee that the adversary’s channel is noisier than the one of the legitimate partner. In a general communication model, it is possible that the received signal of the intended receiver is worse than the received signal of the eavesdropper.