Revocable and Privacy‐Preserving CP‐ABE Scheme for Secure mHealth Data Access in Blockchain

ABSTRACT Innovations in technology are revolutionizing healthcare, driving a shift toward patient‐centric smart healthcare systems. Mobile health (mHealth) leverages innovations in wearable sensors, telecommunications, and IoT to establish a novel healthcare model that prioritizes the patient, enabling real‐time monitoring, personalized interventions, and improved access to care, ultimately fostering a proactive approach to health management and enhancing overall patient outcomes. However, safeguarding patient data transparency, security, and privacy within mHealth systems presents significant challenges, particularly concerning personal health records (PHR). Ciphertext‐Policy Attribute‐Based Encryption (CP‐ABE) offers a competent answer to facilitating one‐to‐many data sharing in healthcare environments. Nevertheless, several issues must be addressed before CP‐ABE can be widely deployed. These include the need for timely and effective attribute revocation when user attributes change, resistance to collusion attacks, and ensuring data integrity. This paper proposes a revocable and secure fine‐grained access scheme using blockchain and CP‐ABE. We compare four prominent state‐of‐the‐art schemes through comprehensive experimentation with our proposed approach. Our results demonstrate the relative performance of our scheme, showing a significant reduction in computational costs. Specifically, the key generation cost is reduced by 35% to 67%, and the encryption cost is reduced by 26% to 39%. A detailed analysis of communication, computational, and storage overhead reveals that our suggested solution offers a distinct advantage in terms of efficiency. The Scyther tool is employed to verify the security measures and assess the accuracy of proposed methodologies, subsequently conducting experiments to showcase its efficacy.