Arbitrary Jamming Can Preclude Secure Communication

Date Added: Nov 2009
Format: PDF

The authors investigate the effect of certain active attacks on the secrecy capacity of wiretap channels by considering arbitrarily varying wiretap channels. They establish a lower bound for the secrecy capacity with randomized coding of a class of such channels and an upper bound for that of all such channels. They show that if the arbitrarily varying wiretap channel possesses a bad "Averaged" state, namely one in which the legitimate receiver is degraded with respect to the eavesdropper, then secure communication is not possible.