HCAC-EHR: hybrid cryptographic access control for secure EHR retrieval in healthcare cloud

Technology that is perfect is free of vulnerability. Technological growth offers users online data storage and access to it from anywhere. Cloud computing is a model that provides data storage on a contract facility and a slew of different services. Today, online data relating to health is inevitably stored and managed. These health records comprise data that includes X-ray images, scanned images, therapy procedures, medical prescriptions, and patient information. Medical professionals use the stored health data for diagnosis, patients for their understanding, and government and insurance companies for further follow-up. Since multiple category of users want access to health data, data needs protection and to be stored with extreme security before being stored online in the form of electronic health records (EHRs) with proper access control mechanisms. To this end to provide secure cloud storage, we propose a novel scheme by implementing a hybrid cryptography algorithm in which we use Improved Key Generation Scheme of RSA (IKGSR) algorithm to encrypt health data and Blowfish algorithm for key encryption. We follow steganography-based access control for key sharing by means of substring indexing and keyword search mechanism to efficiently retrieve the encrypted data. We measure performance evaluation as well as the security of the proposed method and compare with existing hybrid method consider New York State Department of Health dataset. The results clearly confirm that our method provides better security and also retrieves data efficiently.