  We study communication systems over state-dependent channels in the presence
of a malicious state-aware jamming adversary. The channel has a memoryless
state with an underlying distribution. The adversary introduces a jamming
signal into the channel. The state sequence is known non-causally to both the
encoder and the adversary. Taking an Arbitrarily Varying Channel (AVC)
approach, we consider two setups, namely, the discrete memoryless
Gel'fand-Pinsker (GP) AVC and the additive white Gaussian Dirty Paper (DP) AVC.
We determine the randomized coding capacity of both the AVCs under a maximum
probability of error criterion. Similar to other randomized coding setups, we
show that the capacity is the same even under the average probability of error
criterion. Even with non-causal knowledge of the state, we prove that the
state-aware adversary cannot affect the rate any worse than when it employs a
memoryless strategy which depends only on the instantaneous state. Thus, the
AVC capacity characterization is given in terms of the capacity of the worst
memoryless channels with state, induced by the adversary employing such
memoryless jamming strategies. For the DP-AVC, it is further shown that among
memoryless jamming strategies, none impact the communication more than a
memoryless Gaussian jamming strategy which completely disregards the knowledge
of the state. Thus, the capacity of the DP-AVC equals that of a standard AWGN
channel with two independent sources of additive white Gaussian noise, i.e.,
the channel noise and the jamming noise.
