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:
Dec. 13, 2016
Filed:
Sep. 19, 2005
Hongxia Jin, San Jose, CA (US);
Jeffrey Bruce Lotspiech, Henderson, NV (US);
Sigfredo Ismael Nin, Morgan Hill, CA (US);
Hongxia Jin, San Jose, CA (US);
Jeffrey Bruce Lotspiech, Henderson, NV (US);
Sigfredo Ismael Nin, Morgan Hill, CA (US);
INTERNATIONAL BUSINESS MACHINES CORPORATION, Armonk, NY (US);
Abstract
The present invention provides a method performed on a computer of preventing re-use of compromised keys in a broadcast encryption system. In an exemplary embodiment, the method includes (1) incorporating a particular set of Sequence Keys assigned by a license agency into individual receivers, (2) assigning a Sequence Key Block (SKB) by the license agency to at least one distributed protected file, (3) performing incremental cryptographic testing by the individual receivers to determine if a selected Sequence Key from the set of Sequence Keys is compromised, (4) if the selected Sequence Key is not compromised, decrypting the file, and (5) if the selected Sequence Key is compromised and if a subsequent Sequence Key from the set of Sequence Keys is available, selecting the subsequent Sequence Key.