A Caltech Library Service

Document copying deterrent method

Brassil, John T and Low, Steven H. and Maxemchuk, Nicholas F. and O'Gorman, Lawrence P. (2000) Document copying deterrent method. Patent number: US006086706.

[img] PDF (US Patent no. US006086706) - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


The present invention is directed to a method of deterring the illicit copying of electronically published documents. It includes utilizing a computer system to electronically publish a plurality of copies of a document having electronically created material thereon for distribution to a plurality of subscribers and operating programming within the computer system so as to perform the identification code functions. The steps are to encode the plurality of copies each with a separate, unique identification code, the identification code being based on a unique arrangement of the electronically created material on each such copy; and, creating a codebook to correlate each such identification code to a particular subscriber. In some embodiments, decoding methods are included with the encoding capabilities. The unique arrangement of the electronically created material may be based on line-shift coding, word-shift coding, or feature enhancement coding (or combinations of these) and may be effected through bitmap alteration of document format file alteration.

Item Type:Patent
Related Patents:US5629770A, CA2136166C, EP0660275B1, JP3136061B2, DE69421255T2
Patent Classification:Current U.S. Class: 156/277; 235/375; 235/385; 235/454; 283/901; 360/46; 382/100; 382/307. Current CPC Class: G03G 21/04 (20130101); G07D 7/004 (20130101); G07D 7/20 (20130101); G07F 7/08 (20130101); H04N 1/32203 (20130101); H04N 1/32208 (20130101); H04N 1/32219 (20130101); H04N 1/32261 (20130101); G07D 7/0047 (20170501); H04N 2201/3233 (20130101); H04N 2201/324 (20130101); H04N 2201/327 (20130101); Y10S 283/901 (20130101). Current International Class: G03G 21/04 (20060101); G07D 7/00 (20060101); G07D 7/20 (20060101); G07F 7/12 (20060101); H04N 1/32 (20060101); B32B 031/00 ().
Patent Assignee:AT&T Corp, Lucent Technologies Inc
Related URLs:
URLURL TypeDescription Patents site Patent Office
Low, Steven H.0000-0001-6476-3048
Additional Information:Publication number US6086706. Publication type US Grant. Publication date July 11, 2000. Application number US08170619. Filing date December 20, 1993. Priority date December 20, 1993.
Record Number:CaltechAUTHORS:20170810-102749497
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:80081
Deposited By: Linqi Guo
Deposited On:21 Sep 2017 22:42
Last Modified:09 Mar 2020 13:19

Repository Staff Only: item control page