United States Patent p9]
Morris
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US005530751A [ii] Patent Number: 5,530,751 [45] Date of Patent: Jun. 25,1996
[54] EMBEDDED HIDDEN IDENTIFICATION CODES IN DIGITAL OBJECTS
[75] Inventor: Dale C. Morris, Menlo Park, Calif.
[73] Assignee: Hewlett-Packard Company, Palo Alto, Calif.
[21] Appl. No.: 269,807
[22] Filed: Jun. 30,1994
[51] Int. CI.6 H04L 9/00
[52] U.S. CI 380/4
[58] Field of Search 380/4, 25
[56] References Cited
U.S. PATENT DOCUMENTS
3,609,697 9/1971 Blevins et al 380/4
4,120,030 10/1978 Johnstone 380/4
4,658,093 4/1987 Hellman 380/4
5,208,853 5/1993 Armbruster et al 380/4
5,212,728 5/1993 Glover et al 380/4
5,293,422 5/1994 Loiacono 380/4
5,371,792 12/1994 Asai et al 380/4
5,398,285 5/1995 Borgelt et al 380/4
FOREIGN PATENT DOCUMENTS
0366381 10/1989 European Pat. Off. .
0418964 9/1990 European Pat. Off. .
0496607 1/1992 European Pat. Off. .
0580367 7/1993 European Pat. Off. .
0589459 9/1993 European Pat. Off. .
W092/16944 1/1992 WIPO .
Primary Examiner— Salvatore Cangialosi
Attorney, Agent, or Firm—Howard R. Boyle
[57] ABSTRACT
A method and apparatus for encoding identification information into a stream of digital data representing an object. The digital data representing an object is modified to add embedded identification information into the data. This modification is done such that the resultant changes to the object are not objectionable to the user. By comparing the original digital data to the modified data, the possessor of the original data can recover the embedded identification information. However the identification information is effectively unavailable to anyone not possessing the original data.
8 Claims, 10 Drawing Sheets
