Abstract

Software (programs, videogames, music, movies, etc.) can be authorized for use a given number of times by a base unit after which the base unit (computer, videogame base unit, record player, videorecorder or videodisk player) cannot use that software until the manufacturer sends an authorization for additional uses to the user's base unit. Authorizations may be sent via telephone line, mail, or whatever form of communication is most suited to the application. Authorizations cannot be reused, for example by recording the telephone authorization signal and replaying it to the base unit. Similarly, authorizations can be made base unit specific, so that an authorization for one base unit cannot be transferred to another base unit. This invention also solves the "software piracy problem" and allows telephone sales of software as additional benefits.

Other References

• "New Directions in Cryptography", by Diffie and Hellman IEEE Transaction on Information Theory, vol. 22 #6, 11/76
• "Multiuser Cryptographic Techniques", by Diffie and Hellman AFIPS-Conference Proceedings, vol. 45, pp. 109-112, 6/8/76