Abstract

Let \(q\) be a prime power. We study practical coding schemes at short blocklengths for the semi-deterministic \(q\)-ary erasure wiretap channel (\(q\)E-WTC), in which the legitimate receiver observes a noiseless main channel, while the eavesdropper's channel is modeled as a \(q\)-ary erasure channel (\(q\)EC). It is shown that, under the average total variation distance secrecy metric, nonbinary polar codes with Reed-Solomon kernels achieve the best possible theoretical secrecy rate at any blocklength up to \(q\).