Efficient and revocable privacy-preserving medical data sharing scheme with data integrityEfficient and revocable privacy-preserving medical data...X. Yang, B. Tong

Electronic Health Record (EHR) sharing through cloud systems significantly enhances healthcare service efficiency. To address security and user authorization issues in cloud-based EHRs, Revocable Attribute-Based Encryption (RABE) has been introduced. However, existing RABE schemes may pose privacy risks due to their access policies and can lead to data integrity issues during revocation processes. Furthermore, the efficiency of these schemes’ algorithms needs improvement. This paper proposes a revocable, policy-hiding, and data integrity verification scheme. In this scheme, the cloud service provider implements attribute revocation using proxy re-encryption, allowing data owners to submit only proxy information without re-encrypting data. To protect user privacy from potential exposure through access policies, we split the policy into attribute names and values, embedding the values in keys and ciphertexts during key generation and encryption. Random keys and ciphertexts are also generated to create key components for verifying data integrity. The proposed scheme supports an unrestricted attribute space, enhancing system scalability. Finally, we prove the scheme’s adaptive security and demonstrate its higher efficiency through experimental validation.