Patents - Doug Tygar

Anonymous certified delivery
Linda Jean Camp, Justin D. Tygar and Michael R. Harkavy
U.S. Patent 6,076,078. June 2000

Method and apparatus for purchasing and delivering digital goods over a network
Marvin A. Sirbu, J. D. Tygar, Benjamin T. H. Cox and Thomas Wagner
U.S. Patent 5,809,144. September 1998