Feedback Lunch: Deep Feedback Codes for Wiretap Channels

Abstract--We consider reversely-degraded wiretap channels, for which the secrecy capacity is zero if there is no channel feedback. This work focuses on a seeded modular code design for the Gaussian wiretap channel with channel output feedback, combining universal hash functions for security and learned feedback-based codes for reliability to achieve positive secrecy rates. We study the trade-off between communication reliability and information leakage, illustrating that feedback enables agreeing on a secret key shared between legitimate parties, overcoming the security advantage of the wiretapper . Our findings also motivate code designs for sensing-assisted secure communication, to be used in next-generation integrated sensing and communication methods. ECURE communication can be achieved through key-based cryptography, which relies on securely-shared secret keys, and physical-layer security (PLS), which leverages the physical properties of the channel to ensure data confidentiality [1], [2].