Efficient Mediated Ciphertext-Policy Attribute-Based Encryption for Personal Health Records Systems

Abstract

Personal Health Record (PHR) system is a patientcentered system that patients, and health care providers could securely access the patient's health information through internet. It should be noted that security is an important issue of PHR systems, especially if it is accessible through the open internet. In this paper, we propose an efficient mediated ciphertext-policy attributebased encryption (m-CP-ABE) which can realize attribute revocation instantaneously and support monotonic access structure by using Linear Secret-Sharing Schemes (LSSS). These security measures make our scheme greatly reduce the risk that an unauthorized person could access to a patient's health information contained within a PHR system. At the same time, most of the computational overhead in decryption is outsourced to the mediator side, and leave only a little computational workload to the user side. With development of mobile internet, many users many use the mobile devices to access the PHR systems. Thus, this measure make our scheme be very suitable for the application scenario of mobile internet.