Browse Prior Art Database

UNALTERABLE DOCUMENTS

IP.com Disclosure Number: IPCOM000027758D
Original Publication Date: 1999-Jun-30
Included in the Prior Art Database: 2004-Apr-09
Document File: 2 page(s) / 38K

Publishing Venue

Xerox Disclosure Journal

Abstract

Disclosed is a method of printing documents such that any alteration is detectable. The method comprises the following steps: Step 1 - Define a function F that is applied to a raster image of an original document, yielding a number N. The original document may be copied on a digital copier, a printer, or a facsimile machine.

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XEROX DISCLOSURE JOURNAL

UNALTERABLE DOCUMENTS

Proposed Classification James R. Davis U. S. C1.3991021

Int. C1. G03g 15/04

Disclosed is a method of printing documents such that any alteration is detectable. The method comprises the following steps:

Step 1 - Define a function F that is applied to a raster image of an original document, yielding a number N. The original document may be copied on a digital copier, a printer, or a facsimile machine.

Step 2 - Define an encoding scheme (such as bar coding) for printing the number on the printed page.

Step 3 - Verify that the document has not been altered by scanning it, computing F, reading N and comparing F to N. If the document is unchanged, F should equal N.

DP5828

XEROX DISCLOSURE JOURNAL - Vol. 24, No. 3 May/June 1999 133

[This page contains 1 picture or other non-text object]

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134 XEROX DISCLOSURE JOURNAL, - Vol. 24, No. 3 May/June 1999

[This page contains 1 picture or other non-text object]