RESUMO
The smart health medical system is expected to enhance the quality of health care services significantly. These system keeps patients related record and provides the services over the insecure public channel which may cause data security and privacy concerns in a smart health system. On the other hand, ciphertext attribute-based encryption(CP-ABE) provides possible encrypted data security. There are some security flaws in CP-ABE, where the existing access policies are in the cleartext form for accessing encrypted sensitive data. On the other hand, it supports the small attribute universe, which restricts the practical deployments of CP-ABE. Moreover, outsider adversary observed the communication, which also creates a serious threat to CP-ABE model. To overcome security and privacy risk, efficient access control have been designed and devolved for medical services. Although we also demonstrate the security analysis of Zhang et al.'s scheme, which is vulnerable to inefficient security proof and man in the middle attack. In the proposed scheme, we proposed an efficient and security preserve scheme to overcome the weaknesses of Zhang's et al.'s system. The protocol satisfies the attribute values of the medical user with hidden access policies. It has been proved under the standard model, which ensure the security of the protocol. Moreover, performance analysis comparison shows that the proposed scheme is more efficient than the existing one.