| 摘要 |
PURPOSE:To prevent the foul use of cards with forgery, falsification, etc. by using the optional function value including the non-reversible information as a variable to the collating information. CONSTITUTION:The card use state information 11, for example, is recorded to the 1st recording magnetic layer 3 as the non-reversible information A in a form that is shown in the number of pieces of magnetic inverse bursts. While the balance information 12 on a card 1, for example, is recorded to a certain area of the 2nd recording magnetic layer 5 as the information B. Then a function F(A,B) including both information A and B as variables is recorded to the other part of the layer 5 as the collating information 13 (information C). A comparator 37 judges that the card 1 is correct through a control part 30 as long as the coincidence is obtained between the reference information R and the information C. Thus a new information producing circuit 39 produces the new collating information C'=F(A',B') from the new balance information B' and the non-reversible information A' showing the new use state of the card 1. |
