A lattice‐based searchable encryption scheme with multi‐user authorization for the certificateless cloud computing environment

Abstract

Public key encryption with keyword search (PEKS) is able to enhance cloud data security. On the other hand, the existence of malicious cloud servers and untrusted central authorities, in addition the keyword space faces a low entropy, attackers often launch keyword guessing attacks (KGA), thereby leaking data privacy. Therefore, we use certificateless authentication and proxy re‐encryption technology to construct a lattice‐based verifiable PEKS scheme for Multi‐Data Users (MDU). Certificateless authentication can ensure that our scheme does not require key escrow, and proxy re‐encryption technology allows us to perform multi‐user authorization and use the verification block for data users to ensure the integrity of search results. Security research proves that, under the assumption that the learning with errors (LWE) problem is hard, the ciphertext is indistinguishable and resistant to KGA. Results from experiments show that our scheme is significantly more effective than current schemes.