Enhancing Secret Key Generation for UAV Communications via Codeword Reconstruction

2026-06-15

AI Summary

This work addresses the challenge of degraded physical-layer key generation performance in high-mobility UAV communications, where short coherence times and noise induce significant channel estimation errors. To mitigate this issue, the paper proposes a novel key generation scheme based on channel codeword reconstruction. By designing polarized codewords that effectively separate reliable from unreliable bits, the method dispenses with conventional hard quantization and instead leverages soft-decision decoding to fully exploit the raw channel state information. This approach substantially improves key agreement and generation rates between legitimate users while simultaneously reducing the likelihood that an eavesdropper can derive a consistent key, thereby enhancing overall system security.

Abstract

With the rapid advancement of unmanned aerial vehicle (UAV), ensuring the security of communication links among UAVs has become crucial. In this paper, we propose a novel physical layer key generation scheme based on channel codeword reconstruction. In UAV communications, the high mobility of aerial nodes leads to short channel coherence time, which together with noise causes inevitable channel estimation errors. These errors significantly degrades the performance of wireless channel-based key generation. Therefore, we propose a codeword construction algorithm that achieves a polarization characteristic, which effectively segregates reliable keys from unreliable ones. Compared to the existing quantization-based key generation scheme, our approach maximize the utilization of raw channel information and employ soft-decision decoding to generate key. Simulation results demonstrate that the proposed scheme reduces the key disagreement rate for legitimate users and increases the number of consistently generated keys. Furthermore, our method ensures a lower key consistency rate for eavesdropper, which guarantees system security.

Problem

• UAV communications
• secret key generation
• channel estimation errors
• channel coherence time
• physical layer security

Innovation

• codeword reconstruction
• physical layer key generation
• polarization characteristic
• soft-decision decoding
• UAV communications