RFID tag authentication apparatus and method in RFID system

While being a problem with the privacy (Privacy) resolution by using a hash algorithm is a wireless recognition tag authentication device and method to enable the rapid authentication is disclosed. The RFID medium according to the present invention includes a computing unit for encrypting the hash chain based on the secret information and a memory for storing secret information and the secret group tag information, hash (Hash) algorithm. In addition, tag authentication device of the RFID system according to the present invention includes a DB is stored, grouped the information of the wireless recognition tag containing the secret group information and secret tag information, secret group information search section, and the private tag information in the found group includes; a secret tag information search section to search. In addition, the tag authentication method according thereto is disclosed. According to the invention, by reducing the amount of calculations for finding the same time the tag ID and tag privacy protection can be fast and efficient radio tag authentication. RFID, Tag, Tag, authentication, hash, hash, hash chain, hash chain