| 摘要 |
A validator checks the identity of the holder of a credit card or check by comparing a secret code number derived from the holder with a number derived from the serial number of the credit card or check. The basic components of the validator are a keyboard, a scrambler circuit and a comparator circuit. The scrambler circuit is responsive to the keyboard for receiving a serial number or other indicia from the card as punched into the keyboard. Then a key is pressed to signify end of the card indicia and to switch the keyboard output to the comparator circuit. A number offered by the user is punched into the keyboard; and if the number is correct, the comparator circuit is actuated to indicate validity. Such a machine can use any existing credit card, check, or identification card having a serial number; can operate on serial number and letter combinations of any length; and can operate in a way that is undecipherable for practical purposes.
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