Drones Jittering Enhanced Physical-Layer Key Generation

Physical-layer key generation (PLKG) has gained critical importance for secure drone communications due to its lightweight implementation and adaptability to resource-constrained drones. However, the dominant line-of-sight path in drone channels limits wireless randomness, thereby degrading the key generation rate (KGR). To solve this problem, we propose a novel endogenous drone jittering enhanced PLKG scheme, which integrates the inherent drone jittering randomness to enhance KGR. By analyzing wireless signals and inertial measurement unit (IMU) data in the time-frequency domain, we find that the frequency of drone jittering falls within the 0-50 Hz range. Then, the discrete wavelet transform is used to extract jittering components. We quantize both the wireless signals and the extracted jittering components, then use XOR operation to combine their randomness. This forms a hybrid key generation scheme that enhances PLKG. We experimentally collect extensive wireless signal data and IMU data, and the experimental results show that, compared with the traditional PLKG scheme, the proposed scheme increases KGR by 18.6%. Furthermore, the National Institute of Standards and Technology randomness test confirms that the generated hybrid key meets sufficient randomness standards.