Identity-based searchable attribute signcryption in lattice for a blockchain-based medical system

Electronic healthcare systems can offer convenience but face the risk of data forgery and information leakage. To solve these issues, we propose an identity-based searchable attribute signcryption in lattice for a blockchain-based medical system (BCMS-LIDSASC). BCMS-LIDSASC achieves decentralization and anti-quantum security in the blockchain environment, and provides fine-grained access control and searchability. Furthermore, smart contracts are used to replace traditional trusted third parties, and the interplanetary file system (IPFS) is used for ciphertext storage to alleviate storage pressure on the blockchain. Compared to other schemes, BCMS-LIDSASC requires smaller key size and less storage, and has lower computation cost. It contributes to secure and efficient management of medical data and can protect patient privacy and ensure the integrity of electronic healthcare systems.