ERAHE: Edge-offloaded Robust Attribute-Based Aggregate Scheme Enhanced with Homomorphic Encryption for 5G-Connected Delivery Drones

Uncrewed Aerial Vehicles (UAVs) are emerging as an integral part of delivering packages, food, and medicines for fast and efficient services. They rely on 5G networks offering high-speed, low-latency, and reliable connectivity for the exchange of mission-critical data. The 5G-connected drones remain vulnerable to cyber security attacks, including those impacting confidentiality, authentication, and integrity. In this paper, we present an edge-assisted data aggregation framework that reduces the drone's computation overhead and allow for secure data sharing between the drones and the Ground Control Station (GCS). The framework relies on a multi-level Attribute-Based Encryption (ABE) enhanced with an aggregate scheme using the Homomorphic Encryption (HE) properties. By integrating the property of HE with ABE, we ensure that only authorised entities can decrypt the encrypted messages under the threshold policy. To reduce the computation overhead at drones, we offload most computationally expensive operations in the encryption and decryption phases to an edge server.

Our security analysis demonstrated that the proposed scheme guarantees confidentiality, access control, and key management security while resisting UAV-specific attacks such as eavesdropping, man-in-the-middle attacks and data injection. We validate the proposed scheme using a realistic testbed that includes a Holybro Pixhawk drone and Raspberry Pi. The experimental results demonstrate that the edge-assisted ERAHE framework effectively reduces cryptographic latency and computation burden on UAVs by partitioning expensive operations between the drone and the edge node. ERAHE achieves an optimal balance between cryptographic robustness and lightweight performance, making it well-suited for mission-critical applications.