Wiretap Channels: Nonasymptotic Fundamental Limits

Wei Yang; Rafael F. Schaefer; H. Vincent Poor

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arXiv · 1706.03866

Wiretap Channels: Nonasymptotic Fundamental Limits

Wei Yang·Rafael F. Schaefer·H. Vincent Poor

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Abstract

This paper investigates the maximal secret communication rate over a wiretap channel subject to reliability and secrecy constraints at a given blocklength. New achievability and converse bounds are derived, which are uniformly tighter than existing bounds, and lead to the tightest bounds on the second-order coding rate for discrete memoryless and Gaussian wiretap channels. The exact second-order coding rate is established for semi-deterministic wiretap channels, which characterizes the optimal tradeoff between reliability and secrecy in the finite-blocklength regime. Underlying our achievability bounds are two new privacy amplification results, which not only refine the existing results, but also achieve stronger notions of secrecy.

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Wei Yang, Rafael F. Schaefer, H. Vincent Poor. 2017-06-12. Wiretap Channels: Nonasymptotic Fundamental Limits. https://arxiv.org/abs/1706.03866

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