Bidirectional authentication method and system based on symmetric encipherment algorithm

The invention relates to a bidirectional authentication method and a system based on a symmetric encipherment algorithm. The method comprises: 1) a READER, a TAG and an electronic tag application system database (DB) corporately finish the collision process; 2) DB constructs and sends a certificate discrimination request grouping to an authentication server (AS); 3) sending a certificate discrimination response grouping to DB; 4) sending challenge information grouping to READER; 5) sending authentication request grouping to TAG; 8) sending the authentication response grouping to the READER; 7) sending certificate request grouping to DB; and 8) sending certificate response grouping to the READER. The invention can realize the bidirectional authentication method and the system based on the symmetric encipherment algorithm, which can perform bidirectional authentication and can reasonably utilize equipment performance without secure link between the database and the electronic tag.