A novel two-level secure access control approach for blockchain platform in healthcare

The advent of blockchain technology has ushered a paradigm shift in storage of healthcare data from conventional to online mode. As public ledgers, blockchain platforms provide verifiability of data by all nodes on blockchain. This in turn requires the transactions to be visible to all by default which results in privacy concerns for medical data as they contain sensitive and person-identifiable information that should not be disclosed to everyone. As a result, an access control mechanism is required to maintain regulatory controls over the release and access of medical information to certain entities on blockchain. In this work, we address this issue by proposing a two-level access control technique. We incorporate Ciphertext Policy Attribute-based encryption to provide authorization privileges for various parties involved. After that, Proxy Re-encryption is used to attain secure data transfer and anonymity to the requester only. The data owner is not required to provide the requester with the decryption key and decryption will still be done successfully. This property has not been achieved in previous works. The proposed framework’s security is thoroughly examined. The widely established Burrows–Abadi–Needham (BAN) logic is employed to demonstrate the correctness of the proposed framework’s functionality. We show that our framework provides many new security features compared to its peer proposed models. We use the OMNET++ software to simulate our proposed framework and analyze its storage and computation costs in order to determine its efficiency.