Finite-blocklength performance of polar wiretap codes under a total variation secrecy constraint
This work addresses secure communication for wiretap channels, but it appears incremental as it builds on existing polar code frameworks with a new constraint.
The paper tackles the problem of designing wiretap codes with secrecy constraints by analyzing polarizing codes under a total variation distance secrecy constraint, showing that leakage can be bounded and deriving lower bounds for secrecy rates in finite blocklengths over a binary erasure wiretap channel.
We study the performance of polarizing codes over a degraded symmetric wiretap channel under a total variation distance (TVD) secrecy constraint. We show that the leakage can be bounded by the sum of the TVDs of the bit-channels corresponding to the confidential and frozen bits. In the asymptotic regime, this gives a new criterion to design wiretap codes with vanishing TVD leakage. In finite blocklength, it allows us to compute lower bounds for the secrecy rate of different families of polarizing wiretap codes over a binary erasure wiretap channel.