| 摘要 |
<P>PROBLEM TO BE SOLVED: To make it difficult to decrypt cipher while securing convenience of RFID by including an initial value for random number generation in a cipher frame and sending the cipher frame from an R/W and changing random number seeds for each cipher frame. <P>SOLUTION: The reader/writer 200 generates, before transmission of a down cipher frame, a random number seed based upon a stored value of a first imparted data storage means storing imparted data included in the down cipher frame having been sent last, and performs encryption/decryption based upon random number data generated by a first random number generating means using the random number seed as an initial value. A tag 300 generates, before reception of the down cipher frame, a random number seed based upon a stored value in a second imparted data storage means storing the imparted data included in the down cipher frame having been received last, and performs decryption/encryption based upon random number data generated by the second random number generating means using the random number seed as an initial value. <P>COPYRIGHT: (C)2009,JPO&INPIT |
