A Lightweight Certificateless Authenticated Encryption With Multikeyword Search for IIoT

The rapid evolution of the Industrial Internet of Things (IIoT) has driven unprecedented growth in industrial data volumes. To enhance cost efficiency and data-sharing capabilities, massive amounts of this data are stored in the cloud. Public Key Encryption with Keyword Search (PEKS) technology enables efficient encrypted data retrieval without key management and distribution issues and has been extensively studied for this purpose. However, due to inherent IIoT characteristics—such as heterogeneous data formats, resource-constrained devices, and heightened vulnerability to attacks, existing PEKS schemes face significant limitations: 1) typically restricted to single-keyword searches; 2) prohibitive computational overhead for resource-limited IIoT devices; 3) heightened risks of exploitation by attackers. To address these issues, we propose a lightweight certificateless authenticated encryption with multi-keyword search scheme, named CLAEMKS. It enables efficient multi-keyword search while substantially enhancing computational efficiency by eliminating the intensive bilinear pairing operations. Meanwhile, by leveraging certificateless cryptography, CLAEMKS solves certificate management problems while avoiding key escrow issues. Furthermore, formal security proofs and efficiency analyses are conducted to validate the effectiveness of our proposed scheme. The results demonstrate that CLAEMKS delivers substantial performance and security improvements.