A certificateless keyword searchable encryption scheme in multi‐user setting for fog‐enhanced Industrial Internet of Things

Abstract

AbstractIndustrial Internet of Things (IIoT), an appendage of the Internet of Things (IoT), upgrades conventional industries to intelligent and autonomous industries. It integrates different intelligent terminals, sensors, actuators, mobile devices, cloud computing through wireless communication to enhance operational efficiency and safety. However, it relies on the powerful data processing and unlimited storage capabilities of cloud computing by outsourcing its data and on‐demand services to the cloud server. This introduces privacy and confidentiality issues, and a high cost of data access on IIoT, especially for location bound data retrieval. To enforce confidentiality in IIoT, encryption techniques are being adapted to secure the outsourced data, but not without impeding the data searching operation. Several searchable encryption schemes have been proposed for secure and privacy‐preserving data retrieval in IIoT. However, most of these schemes not only completely relied on the cloud server but also susceptible to inside keyword guessing attack (IKGA). Besides, some of them use high computation intensive cryptography operations that make them computationally intensive for resource‐constrained data users and owners. In this article, we develop a lightweight searchable public‐key encryption scheme. The scheme is provably secure against IKGA. It contains a secure key distribution approach for generating and distributing the symmetric encryption key and allows secure ciphertext data search and retrieval in a multi‐user setting without compromising privacy. Finally, we analyze and evaluate the performance of the proposed scheme by comparing the results with some recent state‐of‐the‐art schemes to quantitatively show the capabilities of the scheme.