Method and system for encrypting Radio-Frequency-Identification Tag using Broadcast Encryption Type

The present invention stores information of radio frequency identification (RF-ID) by encrypting the identity (ID) of the tag server and stored in the RF-ID tag, and further the reader (Reader) allowed to be read by the RF-ID tag in the server, be assigned and, decrypts the encrypted identity (ID) information and the identity (ID) encrypted based on the reader the information read from the RF-ID tag when a read, RF-ID tag in the reader to read the RF-ID tag, Broad relates to a cryptographic method and system of radio frequency identification tag using the cast cryptosystem, According to the present invention, any reader (Reader) to prevent information leakage due to RF-ID when reading out the identification data recorded on the tags, the authorized reader can only read it undesirable reader, and also any you can not allow an attacker to perform an access lock (Access lock) for the RF-ID tag, thereby improving user convenience. RFID, RF-ID tag, encrypted identity, a reader, access to the lock, broadcast, Random Seed, indexes, header, ODS, RPS