RLWE-based public key searchable encryption: securer, faster, and lower end-to-end delay for cloud computing

Cloud storage and computing offer significant convenience and management efficiency in the information era. Privacy protection is a major challenge in cloud computing. Public key encryption with keyword search (PEKS) is an ingenious tool for ensuring both privacy and functionality in certain scenarios, such as ensuring privacy for data retrieval appearing in cloud computing. Despite much attention received, PEKS schemes still face several challenges in practical applications, such as low computational efficiency, high end-to-end delay, vulnerability to inside keyword guessing attacks, and key management defects in multi-user scenarios. In this work, we first propose a post-quantum secure PEKS scheme in the standard model. The resulting PEKS scheme is based on Ring-LWE/ISIS assumptions. Then, we present two extended schemes. The first is a public-key authenticated encryption with keyword search scheme, which prevents servers from initiating inside keyword guessing attacks. The second is an identity-based public-key authenticated encryption with keyword search scheme, which reduces the complexity of key management in practical applications. Theoretical analyses prove that these schemes enjoy high security. Experimental results indicate that these schemes provide lower end-to-end delay and higher computational efficiency compared to similar ones.