A Cloud Data Sharing Mechanism Based on Searchable Encryption and Inner Product Function Encryption

With the rapid development of information technology, data has become a key resource for driving social progress and technological innovation. However, the sharing and utilization of data face serious security challenges, especially in non-trusted environments such as third-party cloud servers. Searchable encryption allows users to search without revealing plaintext information. Boneh et al. introduced searchable encryption in the asymmetric cryptosystem, proposing Public Key Searchable Encryption (PEKS). Inner Product Function Encryption (IPFE) technology allows the decryptor to use the key to decrypt the ciphertext corresponding to the vector, thereby obtaining the inner product of the vector, without revealing any other information. Although these two technologies have performed well in some application scenarios, how to comprehensively apply these technologies in the more complex scenario of cloud data sharing remains a topic worthy of in-depth discussion. Therefore, this paper proposes a data sharing scheme IPFE-PEKS, which integrates index-based public key searchable encryption technology and inner product function encryption technology. By constructing an encryption index structure based on a complete binary tree, it realizes the search of encrypted data keywords. At the same time, it uses asymmetric inner product function encryption methods to protect the index structure and ensure secure access to the index. This paper not only elaborates on the design principles of IPFE-PEKS in detail but also analyzes and verifies its correctness and security. Performance comparison with other existing schemes shows that IPFE-PEKS ensures data security while maintaining high search efficiency.