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Scalable Method for Detection of False Receipts Used to Return Goods

IP.com Disclosure Number: IPCOM000117383D
Original Publication Date: 1996-Feb-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 2 page(s) / 68K

Publishing Venue

IBM

Related People

Cato, RT: AUTHOR

Abstract

False sale receipts are sometimes generated to enable thieves to return stolen items to a store in exchange for cash. Sales receipts are typically printed on the wire matrix printer of a point-of-sale terminal. This type of printing is easy to duplicate on the printer used by many personal computers. Detecting the false receipts is the problem.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Scalable Method for Detection of False Receipts Used to Return Goods

      False sale receipts are sometimes generated to enable thieves
to return stolen items to a store in exchange for cash.  Sales
receipts are typically printed on the wire matrix printer of a
point-of-sale terminal.  This type of printing is easy to duplicate
on the printer used by many personal computers.  Detecting the false
receipts is the problem.

      A series of characters could be printed on the receipt that was
the result of encrypting several parameters.  The parameters are data
that would also be printed on the receipt in unencrypted form and
that would uniquely define the purchase transaction:
  1.  Item's Universal Product Code (bar code)
  2.  Date and Time (hour, minute, and second) of purchase
  3.  Point of Sale Terminal Identifier
  4.  Store Identifier

      Encryption algorithms are available that are virtually
impossible to crack.  The encryption algorithm and key would be kept
secret.  They would be changed periodically, with records kept on
when each particular algorithm and key were used.  The encryption
algorithm and key used could be dependent on any or all of the
parameters printed on the receipt, but most likely it would depend on
the date of purchase.

      When an item is returned, the clerk could enter all the data on
the receipt, including the encrypted sequence of characters.  This
data could also be recorded and reentered via bar code if desired.
The point-of-sale terminal would query a data base in the store
controller to determine the encryption algorithm and key to use to
confirm that sequence of encrypted characters was correct and thus
the receipt was legitimate.

      The above method will act as a deterrent but it is not fool
proof.  I...