Lattice-Based Proxy-Oriented Public Auditing Scheme for Electronic Health Record in Cloud-Assisted WBANs

The integrity auditing of outsourced data is becoming an essential process because an increasing number of people or organizations are opting to store health records in cloud servers to reduce local storage. Most existing public auditing schemes requiring complex certificate management are unsuitable for resource-limited mobile devices and are unable to resist quantum attacks; thus, we propose a lattice-based proxy-oriented public auditing scheme for electronic health records. We construct an identity-based auditing scheme based on the small integer solution to avoid complex certificate management issues. We also introduce the idea of proxy to reduce computing overhead from the user side significantly and enable the application of resource-limited mobile devices. Furthermore, we improve the proposed scheme by integrating the Ethereum blockchain to resist malicious proxies. We prove that the proposed scheme is proxy-protected, unforgeable, and privacy-protected. Results of an efficiency analysis show that our scheme demonstrates high computing efficiency on the user side and comprehensive functions.