Efficient Multikeyword Searchable and Verifiable Data Sharing for Cloud-Edge Collaboration Intelligent Transportation Systems

Intelligent transportation systems (ITSs) are essential for the development of future smart cities. They can improve traffic management, mitigate urban congestion, and provide extensive social services by disseminating traffic data collected from vehicles. To facilitate the exchange of sensory data with other vehicles and alleviate the local storage load, sensory data from vehicles is frequently uploaded to cloud or edge servers. However, current ITS data sharing frameworks exhibit certain security vulnerabilities. In particular, they are unable to support secure multikeyword searches or ensure verifiable retrieval of encrypted information. Moreover, some of the schemes cannot ensure the integrity of the retrieved data. Therefore, we propose an efficient multikeyword searchable and verifiable data sharing (EMKV-ABSE) for cloud-edge collaboration ITS. EMKV-ABSE integrates a multikeyword attribute-based searchable encryption (ABSE) scheme and a tamper-proof consortium blockchain (BC). In EMKV-ABSE, we store the keyword indexes and ciphertext hashes of the shared data on the BC, which can ensure the integrity and authenticity of the data. Meanwhile, to avoid security and trust issues associated with central search cloud servers, smart contracts are utilized to perform multikeyword searches and verify retrieval results. Furthermore, the EMKV-ABSE scheme outsources the complex computational tasks in encryption and decryption to edge servers, which realizes lightweight computation for resource-constrained users. The security analysis proves that EMKV-ABSE satisfies the indistinguishability under the chosen plaintext attack (IND-CPA) and the chosen keyword attack (IND-CKA) in the standard model. Performance evaluation shows the efficiency and practicability of our scheme.