Granted Patent
Utility
US 4,888,801 · App. 07/188,868
Hierarchical key management system
Inventors:
Robert I. Foster, Robert F. Pfeifer, Thomas J. Mihm, Jr.
Patented Case
View Patent ↗
Granted: Dec 19, 1989
Filed: May 2, 1988
Inventors
Robert I. Foster
Robert F. Pfeifer
Thomas J. Mihm, Jr.
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.