CCRA: Covert Channel-based Reliable Authentication Scheme for UAV-assisted RAN

UAVs can significantly improve the access networks of next-generation mobile networks during the building of smart cities. Drones equipped with base stations can expand the coverage of communication networks and assist more users’ devices to access the 5G/6G network, in which reliable authentication for drones becomes essential. However, traditional authentication methods still utilize the overt channel to transmit identity and key information, which are vulnerable and very easy to be eavesdropped, hijacked, and forged by malicious third parties. Therefore, this paper proposes an authentication scheme (CCRA). It includes 1) covert channels to assist authentication and key negotiation, and 2) a covert channel algorithm (EIDOP). Specifically, CCRA transmits fake identity information, part of the key information, and unimportant data in the overt channel, while using the covert channel to transmit important data and another part of the key for authentication and key negotiation to enhance the reliability of authentication. In addition, this paper proposes an algorithm called EIDOP based on the order of packet delay intervals to establish the covert channel for embedding and hiding important information. Finally, we conduct experiments on physical machines and compare EIDOP with other covert timing mechanisms to conclude that our algorithm has better concealment and latency overhead and still guarantees a very low BER under such circumstances.