Granted Patent
Utility
US 4,987,593 · App. 07/504,878
One-show blind signature systems
Inventor:
David Chaum
Patented Case
View Patent ↗
Granted: Jan 22, 1991
Filed: Apr 5, 1990
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.