Enhancing Security for Cloud-Based Electronic Health Records through Context-Aware Access Controls

Cloud-based electronic health records (EHRs) are increasingly vulnerable to insider threats, privacy issues, and fine-grained access. Modern state-of-the-art techniques, such Ciphertext-Policy Attribute-Based Encryption (CP-ABE), some-times have scaling problems in actual healthcare settings, high computational costs, and restricted revocation possibilities. In order to overcome these drawbacks, we provide a hybrid security system that integrates symmetric Fernet encryption with CP-ABE, together with a Trusted Third Party (TTP) for key management, policy enforcement, and dynamic role-based access. A time-bound access control mecha-nism, user revocation, and real-time access auditing are all supported by the system. Under a 500-user load with 50 transactions per second, our solution, which was cre-ated using Flask and React.js on a cloud-backed Ubuntu server, exhibits minimal latency—150 ms for registration, 120 ms for login, and 200 ms for 1 MB EHR upload. According to experimental findings, the suggested approach outperforms current methods in terms of cryptographic efficiency and computing cost. Because of this, our platform is useful for actual EHR implementations in addition to being scalable and safe.