05499298 is referenced by 190 patents and cites 4 patents.

The present invention is a method and apparatus for controlling the dissemination of digital information. Digital information is structured logically to incorporate usage history and allowable access window before it is encrypted in a header portion and a body portion. The end user accesses the digital information with a tamper-proof controlled information access device by decrypting the digital information. A controller disposed in the controlled information access device permits end users to access transparently uncontrolled information. Controlled digital information will be accessed as long as the conditions specified by the information provider are met. In one embodiment of the present invention, controlled information is disseminated in an off-line manner while the second embodiment of the present invention disseminates controlled digital information in an on-line manner.

Title
Controlled dissemination of digital information
Application Number
8/210174
Publication Number
5499298
Application Date
March 17, 1994
Publication Date
March 12, 1996
Inventor
Mohan S Kankanhalli
Singapore
SG
Weiguo Wang
Singapore
SG
Arcot D Narasimhalu
Singapore
SG
Agent
Lawrence Y D Ho
Assignee
National University of Singapore
SG
IPC
H04L 9/00
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