Granted Patent
Utility
US 4,759,064 · App. 06/784,999
Blind unanticipated signature systems
Inventor:
David Chaum
Patented Case
View Patent ↗
Granted: Jul 19, 1988
Filed: Oct 7, 1985
Inventor
David Chaum
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.