Capacity-Equivocation Region of the Gaussian MIMO Wiretap Channel

TL;DR

This paper characterizes the full capacity-equivocation region of the Gaussian MIMO wiretap channel, detailing achievable rates for common and private messages while ensuring secrecy from eavesdroppers.

Contribution

It provides the complete capacity-equivocation region for the Gaussian MIMO wiretap channel, confirming the sufficiency of Gaussian auxiliary variables for this characterization.

Findings

Derived the entire capacity-equivocation region.

Confirmed Gaussian auxiliary variables are sufficient.

Enhanced understanding of secure communication limits.

Abstract

We study the Gaussian multiple-input multiple-output (MIMO) wiretap channel, which consists of a transmitter, a legitimate user, and an eavesdropper. In this channel, the transmitter sends a common message to both the legitimate user and the eavesdropper. In addition to this common message, the legitimate user receives a private message, which is desired to be kept hidden as much as possible from the eavesdropper. We obtain the entire capacity-equivocation region of the Gaussian MIMO wiretap channel. This region contains all achievable common message, private message, and private message's equivocation (secrecy) rates. In particular, we show the sufficiency of jointly Gaussian auxiliary random variables and channel input to evaluate the existing single-letter description of the capacity-equivocation region due to Csiszar-Korner.