HCCAS: A hierarchical consensus-based certificateless aggregate signcryption scheme for drone networks

Drone networks are dynamic and cooperative networks composed of multiple drones through wireless communication, which are widely used in search and rescue, patrol, and monitoring missions. Although multi-drone collaboration alleviates the limitations of individual drones in terms of computational and communication capabilities, large-scale deployments still face dual challenges of data security and communication efficiency. To address these issues, we propose a hierarchical consensus-based certificateless aggregate signcryption called the HCCAS scheme. Within each local airspace, a drone with superior computational and communication capabilities is elected as a local leader using the PBFT consensus algorithm. This local leader is responsible for aggregating the signcryption from all drones within its region. Subsequently, local leaders elect a global leader via the RAFT consensus algorithm, which transmits the total aggregated signcryption to the ground control station. In addition, HCCAS incorporates a pseudonym validity mechanism to provide conditional identity privacy protection. An efficient forgery localization mechanism based on a two-dimensional array is also designed, significantly reducing the computational overhead during verification. Compared with existing schemes, HCCAS achieves multiple security goals while reducing average computational cost and communication overhead by 52.09% and 39.69%, respectively. These results indicate enhanced adaptability and practicality in resource-constrained environments.