The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 20, 2005
Filed:
Feb. 20, 2001
Ronald Fagin, Los Gatos, CA (US);
Jeffrey Bruce Lotspiech, San Jose, CA (US);
Nimrod Megiddo, Palo Alto, CA (US);
Dalit Naor, Palo Alto, CA (US);
Simeon Naor, Palo Alto, CA (US);
Ronald Fagin, Los Gatos, CA (US);
Jeffrey Bruce Lotspiech, San Jose, CA (US);
Nimrod Megiddo, Palo Alto, CA (US);
Dalit Naor, Palo Alto, CA (US);
Simeon Naor, Palo Alto, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
An encryption key matrix has rows grouped into segments, with a set of one segment per column establishing a slot. Slots are assigned to device manufacturers, with the keys of the slots then being assigned to decryption devices made by the respective manufacturer. In generating the slots, the number 'q' of segments in a column is first defined such that a predetermined maximum number of devices can be revoked devices (in that all the keys held by the device are revoked) while ensuring that a good device remains a functional device with a probability of at least (1−Q), wherein Q is a predefined device confidence. Once the number 'q' of segments has been defined, the slots themselves are defined in a provably non-discriminatory fashion using an error-correcting code such as a Reed-Solomon code. With this invention, overlap between slots can be minimized to minimize the possibility that the key set of an innocent device might be inadvertently revoked when the keys in the slots of a “bad” manufacturer are revoked.