BCASE-SHC: Blockchain-based Certificateless Authenticated Asymmetric Searchable Encryption for Smart HealthCare

Abstract Nowadays, data has become the cornerstone of any organization's assets. However, this poses significant challenges for organizations, including the production, management, transfer and protection of data. To overcome these challenges, many organizations have adopted information outsourcing and resource sharing, with cloud computing that is the most popular outsourcing technology. Cloud computing offers various attractive features such as data availability, elasticity, and ubiquitous computation. However, the utilize cloud computing also introduces confidentiality and privacy concerns. One solution to address this problem is encryption. However, traditional encryption prevents selection of desired documents, which is crucial in big data scenarios. To enable search capability, researchers introduced searchable encryption which has drawbacks such as keyword guessing attacks, malicious service providers, lack of trust, data integrity, and fairness. In this paper, we propose a solution that leverages blockchain technology to data integrity and data availability insurance, fair payment, and establish trust among the involved parties. Additionally, we present a certificate-less authenticated asymmetric searchable encryption scheme to address challenges such as data owner and receiver identity and keyword guessing attacks. This scheme is implemented using a smart contract, and we have evaluated its efficiency and proved it is operational.