  This paper confronts the pressing challenges of sixth-generation (6G)
wireless communication networks by harnessing the unique capabilities of
Unmanned Aerial Vehicles (UAVs). With the ambitious promises of 6G, including
ultra-reliable 1 Tbps data delivery and ultra-low latency, the demand for
innovative solutions becomes imperative. Traditional terrestrial base stations,
though effective, exhibit limitations in scenarios requiring ubiquitous
connectivity, prompting the integration of UAVs. In response to these
challenges, we introduce a comprehensive solution. This involves UAVs
collaboratively downloading desired content from service providers, and
subsequently establishing secure connections with users for efficient content
exchange. Accordingly, we introduce two new protocols: a collaborative group
data downloading scheme among UAVs called SeGDS, and SeDDS for secure direct
data sharing through out-of-band autonomous Device-to-Device (D2D)
communication. Leveraging certificateless signcryption and certificateless
multi-receiver encryption, these protocols offer lightweight, certificate-free
solutions with features such as user revocation, non-repudiation, and mutual
authentication. Prioritizing high availability, the proposed protocols
effectively detect Denial of Service (DoS) and free riding attacks. A thorough
evaluation underscores the superiority of the proposed protocols in both
security and efficiency over existing models; SeDDS reduces overall computation
by 3x, imposing a lighter communication load on UAVs, while SeGDS meets swarm
UAV security requirements, reducing communication costs by 4x with low
computation cost.
