| 摘要 |
<p>PURPOSE:To make it difficult to alter a magnetic card provided with a read part, a write part and a key part and to enhance security by revising the data of the key part whenever the data are newly written in the write part. CONSTITUTION:The magnetic card C is provided with an R/O part 1 storing read only data where the kind of a card main body Co is fixed, an R/W part 2 writing the present value data of the card main body Co and the new value data by being and a variable key part 3a recording the variable key data. In the variable key part 3a, prescribed key data are written whenever the card main body Co is inserted into a card processing equipment and used. The key data are variable, and are revised by using, e.g. a random number. Thus, even if processing algorithm is intended to be decoded from the variable key part 3a, the data in the R/W part 2 are changed successively, and the decoding of the processing algorithm becomes impossible, and the alteration is made impossible.</p> |
