Granted Patent
Utility
US 5,131,039 · App. 07/609,519
Optionally moderated transaction systems
Inventor:
David Chaum
Patented Case
View Patent ↗
Granted: Jul 14, 1992
Filed: Nov 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.