This project propose, cloud-assisted Industrial Internet of Things (IIoT) has become pervasive in the modern enterprises, because it supplies a promising way to transform the operation mode of existing industrial facilities and brings a great progress in enhancing the production efficiency and lowering the manufacturing cost. In order to preserve the privacy of enterprises, the sensitive industrial data need to be encrypted prior to being uploaded to the cloud. Recently, certificateless encryption with keyword search (CLKS) was introduced to resolve the problem of encrypted data retrieval in cloud assisted IIoTs. However, the existing CLKS schemes only support single recipient keyword search and lie on the time consuming bilinear pairing that is disliked by the resource constrained IIoT devices. Moreover, most of the existing CLKS schemes are vulnerable to the keyword guessing attack, and thus fail in protecting the privacy of searched data. In this project, we develop a privacy preserving and pairing free multi recipient CLKS scheme for cloud assisted IIoTs. The proposed scheme has the following merits: (1) supporting multi recipient keyword search function; (2) requiring no costly bilinear pairing operations; (3) providing resistance against keyword guessing attacks. The performance comparison and analysis demonstrate that it is more efficient than the existing CLKS schemes and is appropriate for the cloud-assisted IIoTs.