Granted Patent
Utility
US 5,136,647 · App. 07/561,888
Method for secure time-stamping of digital documents
Inventors:
Stuart Haber, Wakefield S. Stornetta, Jr.
Patented Case
View Patent ↗
Granted: Aug 4, 1992
Filed: Aug 2, 1990
Inventors
Stuart Haber
Wakefield S. Stornetta, Jr.
Assignee (at issue)
Bell Communications Research, 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.