| 摘要 |
<P>PROBLEM TO BE SOLVED: To enhance safety of information security by generating a sub code for initialization and changing of a main code with an expiration date, and adding temporal limitation to initialization and changing of a main ID code. <P>SOLUTION: An image formation system comprises an image formation device and an information processing device. The image formation device comprises an authentication processing part which calculates a serial number and an effective period of a sub code from the inputted sub code, and permits changing of a main code if the calculated serial number matches the serial number of the image formation device and the effective period has not expired yet. The information processing device comprises a processing part which is dedicated to the image formation device corresponding the serial number so that the image formation device can perform decryption, and generates the sub code in which data showing the effective period calculated based on the data for effective period setting which corresponds to the serial number is embedded. <P>COPYRIGHT: (C)2012,JPO&INPIT |
