Disguised Full-Duplex Covert Communications

Area of Science:

• Information Theory
• Wireless Communications
• Network Security

Background:

• Covert communication enhances security beyond cryptography and physical layer methods.
• Existing methods aim to hide the existence of communication links.
• This research explores advanced covertness by disguising node functionality.

Purpose of the Study:

• To analyze a system where a full-duplex node covertly transmits messages to a hidden receiver.
• To determine the achievable covert rate by optimizing public data rate and transmit power.
• To evade warden surveillance by minimizing detection error probability.

Main Methods:

• Mathematical modeling of a covert communication system with a full-duplex destination node.
• Optimization of destination node's public data rate and transmit power.
• Analysis of worst-case detection error probability (DEP) for warden surveillance.

Main Results:

• Closed-form solutions for achievable covert rate are derived.
• Numerical results demonstrate the impact of system parameters on covert rate.
• Destination transmit power inversely affects covert rate based on source transmit power levels.

Conclusions:

• The study provides an information-theoretic performance guideline for advanced covert communication.
• Future research directions include practical modulation schemes and imperfect channel state information analysis.
• The proposed method offers enhanced covertness by node functional disguise.