The low-Earth orbit (LEO) satellite constellation holds immense potential for offshore wind farm surveillance since it can provide all-day and all-weather monitoring capabilities facilitated by satellite collaboration. However, it faces significant challenges. First, limited downlink transmission bandwidth constrained by ground stations and constraint on-orbit resources necessitate selective data downloads, focusing only on differences between consecutive data sets. Second, a passively injected satellite in open space poses a risk of unauthorized data extraction from neighboring satellites. Third, onboard energy constraints limit the feasibility of computationally intensive cryptographic operations. To tackle these challenges for the first time, we propose a novel secure and efficient on-orbit comparison (SEOC) scheme. Our solution begins with introducing a lightweight matrix encryption-based secure inner product (MSIP) technique tailored for secure on-orbit comparison. We further enhance communication efficiency by integrating a Cuckoo filter to reduce costs, complementing a novel difference comparison tree (DCTree) structure to manage false positives. Through comprehensive security analysis, the $\textsf {MSIP}$ technique achieves selective security, and the $\textsf {SEOC}$ scheme is secure under the universally composable (UC) framework. At last, performance evaluations demonstrate the high efficiency of our approach in terms of computational costs and communication overheads, which adapts to the limited on-orbit resources.

Low Earth orbit (LEO) communication satellite constellation provides network service to remote areas without terrestrialnetwork coverage. In sparsely populated areas, the deployment of ground stations is also scarce, due to geographic constraints and the lack of terrestrial backhaul. Due to the constant orbiting of the satellite constellation, location management in LEO satellite-assisted vehicular networks faces the challenges of the dual mobility of access points and users. In this paper, we propose a privacy-preserving location management scheme in an LEO satellite network with sparsely deployed ground stations. Specifically, the proposed scheme exploits the RSA-based accumulator and the Non-Interactive Proof-of-Knowledge of Exponent ( - ) protocol to verify the linkages between satellites and vehicles. Meanwhile, our scheme combines the homomorphic Symmetric Homomorphic Encryption ( ) cryptosystem, the Secure Less than ( ) protocol, and the KdTree structure, to identify the potential set of accessing satellites. Security analysis shows that the proposed scheme achieves privacy preservation and authentication. Performance evaluations show that ours achieve high computation and communication efficiency.