RFID authentication system and authentication method based on position privacy cloud

The invention discloses an RFID authentication system and an authentication method based on position privacy cloud, and aims to solve the problems that the position privacy of a reader is revealed, and the tag calculation complexity degree is too high. The authentication method mainly comprises the following steps: transmitting an authentication request to a tag through the reader; responding to the request of the reader through the tag; forwarding the response of the tag to a cloud database server to check and match through the reader through position privacy cloud; feeding back succeeded matching to the reader through the cloud database server; decrypting messages through the reader, completing authentication on the tag, and calculating records required to be updated; after the cloud database server is updated, transmitting verification information to the reader; transmitting privacy values to the tag through the reader in an encryption manner; verifying through the tag, completing authentication on the reader, and updating the privacy value. Due to adoption of the position privacy cloud, the position privacy of the reader is effectively protected, the privacy security problem in the radio frequency recognition and authentication process is successfully solved, the application requirements of RFID are met, and the RFID authentication system and the authentication method are wide in application prospect.