Blockchain-Enabled Searchable Encryption for Secure and Efficient Sharing of IoHT-Generated Electronic Medical Records in Cloud-Based Healthcare

Protecting the security of data generated by wearables and monitoring devices is critical in smart wards, especially when healthcare schemes use cloud storage services to save patients' Electronic Medical Records (EMRs). These devices operate in wireless communication environments, where data integrity and transmission security are vital. Despite the fact that encryption helps protect information, it often reduces the benefits of sharing the information generated using Internet of Health Things (IoHT) devices with others. As individuals increasingly share their EMRs with third parties, developing an effective searchable encryption framework for sharable EMRs remains a crucial task. Furthermore, cloud-based access control might result in heavily centralized control. To address this, we proposed a blockchain-assisted technique for sharable EMRs that incorporates a searchable encryption scheme compatible with a resource-constrained wireless system that does not require any secure channel. The encrypted EMRs are saved in the cloud, while the encoded keyword indexes are kept on the blockchain, assuring tamper resistance, integrity, and accountability of the encrypted indexes. Our technique also enables exact recovery of encrypted EMRs using a multi-keyword search, removing the necessity for third-party verification. Compared to prior searchable encryption systems, our technique reduces storage costs while increasing computational efficiency. Furthermore, our system is immune to keyword-guessing attacks, a must-needed one that many previous solutions fail to address wireless medical data security.