An efficient and provably-secure certificateless public key encryption scheme for telecare medicine information systems.

Telecare Medicine Information Systems (TMIS) promote the traditional medical and healthcare services by information and communication technology. Since the physician and caregiver can monitor the patient's physiological condition remotely in TMIS, the confidentiality of this sensitive data should be protected, which is the key issue in the Health Insurance Portability and Accountability Act. In this paper, we propose an efficient certificateless public key encryption scheme without bilinear pairing for TMIS. Our proposal is proved to be secure in the random oracle model under the hardness assumption of computational Diffie-Hellman problem. Moreover, after modifying the original model of the certificateless encryption, this scheme achieves Girault's trust level 3. Compared with the related protocols, the perform evaluations show that our scheme is more efficient and appropriate to collocate with low power mobile devices for TMIS.