MKSS: An Effective Multi-authority Keyword Search Scheme for edge–cloud collaboration

The rapid development of cloud computing motivates Internet of Things users to outsource their data to enjoy value-added cloud services: data storage, data sharing, etc. To provide reliable but searchable results, searchable encryption (e.g., Ciphertext-Policy Attribute-Based Keyword Search (CP-ABKS)) become an area of active research. One major drawback of existing CP-ABKS designs lies in the private key being generated and distributed by a trusted Central Authority (CA), which is a single point of failure/attack. Another limitation is that the cloud server may return forged or incomplete query results to the data user. This paper proposes a novel Multi-authority Keyword Search Scheme for edge–cloud collaboration (MKSS). To protect the security of the private key, we design a private key generation algorithm based on secure multi-party computation. To preserve the integrity of search results, we construct an efficient verification algorithm that detects forged or incomplete results. We evaluate the security and performance of our protocol using real-world datasets to demonstrate robustness and efficiency. Our construction advances the existing body of research towards secure and efficient keyword search protocols in cloud systems.