Granted Patent
Utility
US 5,208,853 · App. 07/756,702
Method and apparatus for usage protection of data files using split key and unique variable
Inventors:
Peter J. Armbruster, Paul R. Kennedy
Patented Case
View Patent ↗
Granted: May 4, 1993
Filed: Sep 9, 1991
Inventors
Peter J. Armbruster
Paul R. Kennedy
Assignee (at issue)
Motorola, Inc.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.