A privacy protection authentication method based on a wireless body area network may be applied to a smart home care system. The method provides an authentication method for two-way authentication and key verification between a device and a cloud server, can ensure identities of the device and the cloud server to be valid and prevent network information security from being affected by external invasion attacks. A physical unclonable function and an elliptic curve cryptography algorithm are introduced to encrypt key data in the authentication process, so that the whole authentication process is in a safe environment, and the security of the authentication process is further improved through adding and removing functions of a third-party identity. The privacy protection authentication protocol method can resist replay attacks and smart card impersonation attacks, the whole authentication process is safe and efficient, and has a high application value in smart home care scenes.