| 摘要 |
To improve security and prevent fraudulent use of a credit card (40), there is provided a verification device (10) which is separate from the credit card and bears different data, e.g. on a magnetic strip. At the time of a transaction the data is read (32) to verify that it relates to the credit card in use before the transaction is allowed to proceed. The data is preferably read by a separate reader (24) so that it never needs to leave the hands of the owner, although a common reader could be used. A PIN number may also be entered (24) at the time of the transaction for verification. Preferably the different data comprises (a) data enabling an initial verification check at the reader; (b) data which is essentially unique to a particular card for a second verification at a central computer; and (c) variable data for verification at the central computer, and which is thereafter altered and rewritten both at the central computer and on the verification device. |
