Two-way access authentication method

A two-way access authentication method, comprising by a first entity an access authentication request message to a second entity according to system parameters predefined by an authentication server, and verifying by the second entity a signature signed by the first entity, and if the signature is correct, calculating by the second entity a shared master key of the second entity, wherein the system parameters comprise a product N of two large prime numbers, an integer e satisfying gcd(e,φ(N))=1 an integer d satisfying ed≡1(mod φ(N)) and a strong one-way hash function h, with φ( ) being the Euler's totient function, wherein the integer d is the system's private key which is secretly maintained by the authentication server, the authentication server generates for the ith entity a private key as gi←IDid (mod N), where IDi represents an identity of the ith entity, and i=1, 2;

• sending by the second entity an identity verification request message to the authentication server, verifying by the authentication server validity of identities of the first and second entities and sending an identity verification response message to the second entity, and verifying by the second entity the identity of the first entity according to the identity verification response message;
• if the identity of the first entity is correct, generating by the second entity an access authentication response message, and sending by the second entity the access authentication response message to the first entity, and verifying by the first entity a signature and a message integrity check code of the access authentication response message, and if the signature and the message integrity check code of the access authentication response message are both correct, calculating by the first entity a shared master key of the first entity;
• and
• sending by the first entity an access authentication acknowledgement message to the second entity, verifying by the second entity integrity of the access authentication acknowledgement message, and if the verification is passed, the shared master keys of the first and second entities are consistent, thereby accomplishing access authentication.