The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 09, 1976
Filed:
Oct. 07, 1974
Kurt Ehrat, Zurich, CH;
Gretag Aktiengesellschaft, Zurich, CH;
Abstract
A method and apparatus is described for preparing and assessing machine readable payment documents such as bank or postal checks to avoid fraud. The checks are prepared by enciphering the serial number and the amount for which the check is made out with secret code data to provide a crypto number which is printed on the check with the serial number and the amount. The check is assessed as valid by reading out the printed data and enciphering the amount and serial number with the same secret code data as used when preparing the check to provide a crypto number which is compared with the crypto number read from the check. If the two crypto numbers are the same the check is assessed as valid. The crypto number can be derived from additional data such as the credit card number of the person making out the check, the time and date and the number of the machine preparing the document.