| 摘要 |
PURPOSE:To disable information with high secrecy to be read out after a certain time and then, to erase data, by dividing a data storing area into an ordinary data area and an erase data area, and storing a time to be erased with the erase data. CONSTITUTION:The data storing area 3 of an IC card 1 is divided into the ordinary data storing area 3a and an erase data storing area 3b. In the area 3a, ordinary data D1-Dn-1 corresponding to addresses A1-An-1 are stored. In the area 3b, the data are stored in the form of (Ak.Ak+1) which form the address pairs of (An.An+1), (An+2.An+3),..., and the erase data SDl is recorded in the address Ak, and an erase time Tl in the address Ak+1. When the card 1 is read out by an external device 2, readout is disabled by a control mechanism 2b if an area is the area 3b and the time Tl of the Ak+1 is before the present time, and furthermore, the data is erased. Therefore, the secrecy can be held by recording secret data in the area 3b. |
