Method and arrangement for generating and checking a security imprint

• US 5,953,426 A
• Filed: 02/11/1997
• Issued: 09/14/1999
• Est. Priority Date: 02/11/1997
• Status: Expired due to Term

• Current Assignee: Francotyp-Postalia GmbH (Francotyp-Postalia Holding AG)
• Original Assignee: Francotyp-Postalia GmbH (Francotyp-Postalia Holding AG)
• Inventors: Wagner, Andreas, Thiel, Wolfgang, Windel, Harald
• Primary Examiner(s): Gregory, Bernarr E.
• Application Number:
  US08/798,604
• Time in Patent Office: 945 Days
• Field of Search: 705/401, 705/405, 705/406, 705/410, 380/2, 380/9, 380/49, 380/50, 380/51, 380/54, 380/55, 380/59, 380/23, 380/24, 380/25, 380/29, 380/21
• US Class Current: 380/51
• CPC Class Codes: G07B 17/00435 Details specific to central, non-customer apparatus, e.g. servers at post office or vendor
• CPC Class Codes: G07B 17/00508 Printing or attaching on mailpieces printing mechanisms B41J; security printing B41M3/14; marking methods B41M5/00; inks C09D11/00; record carriers with at least a part designed to carry digital markings G06K19/00
• CPC Class Codes: G07B 17/00661 Sensing or measuring mailpieces weighing G01G19/00
• CPC Class Codes: G07B 17/00733 Cryptography or similar special procedures in a franking system
• CPC Class Codes: G07B 2017/00443 Verification of mailpieces, e.g. by checking databases
• CPC Class Codes: G07B 2017/0058 Printing of code
• CPC Class Codes: G07B 2017/00725 Reading symbols, e.g. OCR
• CPC Class Codes: G07B 2017/00774 MAC (Message Authentication Code), e.g. DES-MAC

Abstract

A method for checking a security imprint in a postage meter machine having a microprocessor includes the steps of encoding data for a security mark pixel image and inserts the encoded data into the remaining, fixed and variable pixel image data during printing. The method includes steps for forming a mark symbol sequence from an encoded combination number which is composed of at least a first number (sum of all postage values since the last reloading date), an optional second number added to said first number, a third number (postage value) and a fourth number (of the serial number), and for enabling a check of the security imprint by a postal authority. Manipulations can be recognized using further data stored and/or calculated in a remote data center. An arrangement conducting a for check includes a mark reader composed of a CCD line camera, a D/A converter, a comparator and an encoder which are connected via an input/output unit to an input unit. A communication link can be established between the meter and the data center to evaluate mark data in a computerized manner.

Claims

1. A method for verifying data formed by a plurality of characters in an indicium comprising characters readable by an optical character reader, comprising the steps of:

reading characters in an indicium using an optical character reader;

retrieving a DES key from a database using a vendor identifier and a device identifier;

computing a MAC dependent on said characters read by said optical character reader and said DES key;

identifying an MAC from the characters read by said optical character reader;

comparing the computed MAC with the MAC read from said indicium; and

acknowledging validity of said indicium given identity of the computed MAC and the MAC obtained from the indicium.