As cloud computing technology matures, along with an increased application of distributed networks, increasingly larger amounts of data are being stored in the cloud, and are thus available for pervasive application. At the same time, current independent medical record systems tend to be inefficient, and most previous studies in this field fail to meet the security requirements of anonymity and unlinkability. Some proposed schemes are even vulnerable to malicious impersonation attacks. The scheme proposed in this study, therefore, combines public and private clouds in order to more efficiently and securely preserve and manage electronic medical records (EMR). In this paper, a new secure EMR authorization system is proposed, which uses elliptic curve encryption and public-key encryption, providing a health care system with both public and private cloud environments with a message authentication mechanism, allowing the secure sharing of medical resources. The analysis shows that the proposed scheme prevents known attacks, such as replay attacks, man-in-the-middle attacks and impersonation attacks, and provides user anonymity, unlinkability, integrity, non-repudiation, forward and backward security.