A secure data sharing scheme based on searchable public key encryption for authorized multi-receiver

Abstract

To ensure data confidentiality, data sharers usually choose to encrypt the data before uploading it to cloud storage. Data sharing is an important way to realize the value of data. Therefore, how to share encrypted data stored in the cloud among authorized users is a pressing issue that needs to be addressed. Public key encryption schemes with keyword search provide an effective solution to this problem. In this paper, we first analyze Yang et al.’ scheme Yang et al. (2023), and point out that the scheme does not realize the indistinguishability of ciphertext and trapdoor. Then, we propose a new data sharing scheme with searchable public key encryption for authorized multi-receiver (SDS-SPKE), which not only realizes the search function, but also realizes the key update, user revocation. Additionally, we provide the security proofs of the scheme, which reveals that our scheme realizes the indistinguishability of ciphertext and trapdoor, and solves the problem of single-key-exposure. Finally, we compare the performance of SDS-SPKE with five other searchable encryption schemes, and the experimental results show that our scheme offers superior efficiency.