A Privacy Preserving Blockchain Framework for Healthcare Data Based on EHR (Electronic Health Records)

Healthcare information is highly sensitive because it includes details such as patient prescriptions, medical history, treatments, and clinical activities. This data is often shared among different stakeholders within the healthcare system, including doctors, laboratories, and other medical professionals. Since patient information is critical, it must be kept accurate, up-to-date, confidential, and accessible only to authorized individuals. Traditional centralized systems used for storing healthcare records can increase security risks, as they create a single point of vulnerability. Therefore, ensuring the privacy and security of medical data while sharing it across multiple entities has become a major concern. This study proposes a privacy-preserving access control framework based on blockchain technology. The framework uses a decentralized approach, where data is managed across distributed systems through consensus mechanisms. This ensures better security, transparency, and integrity of healthcare data. One of the key advantages of blockchain is its immutability, which prevents unauthorized modification of records and protects transactions from tampering. Furthermore, the proposed system considers different participants in the healthcare ecosystem, such as patients, doctors, researchers, and pathology labs, allowing them to share information securely through authorized channels. The framework is implemented and evaluated using Laravel and Hyperledger Fabric, and the results demonstrate improvements in security, regulatory compliance, reliability, scalability, and data accuracy.