Bidirectional authentication method based on intelligent card

An identity authentication method based on an intelligent card comprises a registration step, a login step and an authentication step. The registration step comprises the steps that a user registers with a background server, the background server issues the intelligent card to the user, and two latest random keys and a unique identifier of the intelligent card are stored in each intelligent card.the login step comprises the steps that a user inserts an intelligent card into a card reader to log in THE background server. The authentication step includes that after login success, legality of the intelligent card and the background server is authenticated, wherein the two random keys are digitally signed by using an improved ECC signature method; the digital certificate, the random key and the signature are integrally encrypted by using the shared key through an AES encryption algorithm, and the random key is updated after the smart card successfully authenticates the background server and after the background s