An efficient and secure searchable public key encryption scheme with privacy protection for cloud storage

In the area of searchable encryption, the searchable public key encryption (SPE) is an attractive technique in secure cloud storage. SPE assures the data confidentiality without affecting the usage of the data stored in the cloud. Furthermore, compared with the symmetric searchable encryption, SPE does not require key distribution and management. We investigate the security of the searchable public key encryption based on the traditional Boneh’s framework. Although existing SPE schemes can enable users to search over encrypted data, most of these schemes are vulnerable to the file-injection attack and the insider keyword guessing attack. To mitigate these attacks, we propose an efficient and secure searchable public key encryption with privacy protection (SPE-PP). We then provide a concrete construction of SPE-PP that uses the Diffie–Hellman shared secret key, and we prove it can resist these attacks. Both the theoretical analysis and the experimental results show that our scheme achieves strong security along with high efficiency.