Secure hierarchical multi-modal data sharing scheme in satellite Internet

With the development of satellite Internet, the volume of sensitive multi-modal data is constantly increasing, and its secure storage and access are facing great challenges. The existing data sharing schemes cannot balance search efficiency and privacy access control during the search process. To address the above contradictions, we propose a secure hierarchical multi-modal data sharing scheme in satellite Internet (SHMDS-SI), which ingeniously combines hierarchical access control with searchable encryption, achieving the secure sharing of multi-modal data in satellite Internet. Firstly, the scheme selects specific feature extraction methods to extract features from heterogeneous multi-modal data, and output feature vectors of unified dimensions, improving the efficiency of data processing. Secondly, the scheme designs policy-hidden attribute-based encryption and searchable encryption algorithms, embedding user attributes into data ciphertexts and trapdoors to achieve hierarchical fine-grained access control for encryption and search processes. Finally, the system, through the cloud-edge-end collaborative computation protocol, designates proxy servers to assist users in decryption, effectively reducing the high computing overhead of terminal devices. This paper provides a rigorous proof of the security of the scheme. Meanwhile, theoretical and simulation analyses show that this scheme has a higher search efficiency compared with the existing schemes.