Fair multi-owner search over encrypted data with forward and backward privacy in cloud-assisted Internet of Things

The trend towards the Internet of Things (IoT) technology promises the growth of home and organizational automation in the world. Due to the large amount of IoT data stored in the semi-trust cloud server, the IoT is vulnerable to cyberattacks. Therefore, the privacy violation of outsourced data is an obstacle to efficient IoT data storage. Searchable encryption is a promising solution for secure storage and selective data retrieval. However, achieving desired privacy, performance, and attributes such as dynamics, access control, scalability, and fair arbitration is still a challenge in searchable encryption schemes. In this paper, we propose a fair and dynamic multi-owner searchable encryption scheme wherein dynamics does not leak the sensitive information. In the proposed scheme, the verifiability and fair arbitration, respectively, prevent the malicious cloud servers and malicious users from having any motivation to disrupt the accuracy of the exchanged data. Generating a single trapdoor corresponding to the conjunctive keyword query, a client can search over all documents stored in the cloud, the owner of which has allowed the client to access. We also prove that our scheme is secure against the keyword guessing attack in the standard model. Finally, evaluating the performance of the proposed scheme on a real dataset, we demonstrate its efficiency as well.