Multi-part file encryption for electronic health records cloud

The rapid advancements of mobile technologies promote many applications for public health, such as continuous health monitoring. The inherent mobility of these applications imposes new security and privacy challenges. Since mobile devices usually use public network, such as WiFi, to transfer patient data, patient data is exposed to various security breaches. Moreover, patient data stored on cloud servers are also exposed to malicious attacks. Therefore, it's crucial to encrypt patient data for secure transfer and storage. To address this problem, we present a new access control model for managing patient data. Our approach utilizes a key server for key assignment, which associates a key with each user based on his specific role in medical applications. The doctors, nurses, family members, and insurance companies of a patient can access different sets of patient data from cloud given their keys. Different from existing attribute based encryption, which protects data from inappropriate disclosure for individual files, our design provides a finegrained access control scheme that protects any specified part of a file. Our role-based access control provides high security, accuracy, and update flexibility for patient data management. Performance evaluations of our solution are stated in the paper.