Non-Adaptive Coding for Two-Way Wiretap Channel with or without Cost Constraints

TL;DR

This paper studies the secrecy results for the two-way wiretap channel (TW-WC) with an external eavesdropper under a strong secrecy metric, and employs non-adaptive coding to derive inner bounds on the secrecy capacity regions for the TW-WC under strong joint and individual secrecy constraints.

Abstract

This paper studies the secrecy results for the two-way wiretap channel (TW-WC) with an external eavesdropper under a strong secrecy metric. Employing non-adaptive coding, we analyze the information leakage and the decoding error probability, and derive inner bounds on the secrecy capacity regions for the TW-WC under strong joint and individual secrecy constraints. For the TW-WC without cost constraint, both the secrecy and error exponents could be characterized by the conditional Rényi mutual information in a concise and compact form. And, some special cases secrecy capacity region and sum-rate capacity results are established, demonstrating that adaption is useless in some cases or the maximum sum-rate that could be achieved by non-adaptive coding. For the TW-WC with cost constraint, we consider the peak cost constraint and extend our secrecy results by using the constant composition codes. Accordingly, we characterize both the secrecy and error exponents by a modification of Rényi mutual information, which yields inner bounds on the secrecy capacity regions for the general discrete memoryless TW-WC with cost constraint. Our method works even when a pre-noisy processing is employed based on a conditional distribution in the encoder and can be easily extended to other multi-user communication scenarios.

Figures (1)

• Figure 1: Two-Way wiretap channel with an external eavesdropper.

Theorems & Definitions (25)

• Theorem 1
• Remark 1
• Lemma 1
• Theorem 2
• Lemma 2
• Remark 2
• Lemma 3
• Lemma 4
• Lemma 5
• Lemma 6