Secure and Lightweight Fine-Grained Searchable Data Sharing for IoT-Oriented and Cloud-Assisted Smart Healthcare System

It is a new trend in healthcare informatization construction to build the smart healthcare system by using the Internet of Things (IoT) and cloud. This IoT-oriented and cloud-assisted healthcare system enables the doctor to monitor the patient’s health state to respond to the paroxysmal diseases in real time. Considering the sensitivity of the patient’s privacy, it is necessary to encrypt the cloud-stored health data to prevent the semi-trusted cloud and unauthorized users from accessing them. However, the encrypted health data stored in the cloud brings inconvenience to the retrieval for the data user. In addition, the expensive computational consumption also raises the challenge to the resource-constrained devices in the patient and doctor sides. To support efficient ciphertext retrieval and cope with the performance challenge, in this article we propose a lightweight attribute-based searchable encryption (LABSE) scheme, which realizes fine-grained access control and keyword search, while reducing the computational overhead for the resource-constrained devices. We rigorously prove the semantic security of the proposed LABSE scheme, and analyze other security properties to response the security requirements under the healthcare scenario. Subsequently, we construct a concrete deployment model for LABSE under the healthcare system. We also compare LABSE with the state-of-the-art related schemes in terms of functionality and complexity. Finally, we demonstrate the practicality and performance advantages by the experiment.