An efficient code for Adversarial Wiretap channel

In the (ρ_r, ρ_w)-adversarial wiretap (AWTP) channel model of [13], a codeword sent over the communication channel is corrupted by an adversary who observes a fraction ρ_r of the codeword, and adds noise to a fraction ρ_w of the codeword. The adversary is adaptive and chooses the subsets of observed and corrupted components, arbitrarily. In this paper we give the first efficient construction of a code family that provides perfect secrecy in this model, and achieves the secrecy capacity.