Full-Duplex vs. Half-Duplex Secret-Key Generation
This work addresses security challenges in 5G and IoT systems by enhancing physical-layer key generation, though it appears incremental as it builds on existing models and trade-offs.
The paper tackles the problem of secret-key generation for secure wireless communication by comparing full-duplex (FD) and half-duplex (HD) modes, showing that FD can improve secret-key rates and degrade eavesdropper capabilities under certain conditions, with analysis indicating that perfect self-interference cancellation is not required for gains.
Full-duplex (FD) communication is regarded as a key technology in future 5G and Internet of Things (IoT) systems. In addition to high data rate constraints, the success of these systems depends on the ability to allow for confidentiality and security. Secret-key agreement from reciprocal wireless channels can be regarded as a valuable supplement for security at the physical layer. In this work, we study the role of FD communication in conjunction with secret-key agreement. We first introduce two complementary key generation models for FD and half-duplex (HD) settings and compare the performance by introducing the key-reconciliation function. Furthermore, we study the impact of the so called probing-reconciliation trade-off, the role of a strong eavesdropper and analyze the system in the high SNR regime. We show that under certain conditions, the FD mode enforces a deteriorating impact on the capabilities of the eavesdropper and offers several advantages in terms of secret-key rate over the conventional HD setups. Our analysis reveals as an interesting insight that perfect self-interference cancellation is not necessary in order to obtain performance gains over the HD mode.