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:
Feb. 01, 2011
Filed:
Dec. 11, 2006
Thierry Lelegard, Paris, FR;
Pascal Junod, Vufflens-la-Ville, CH;
Thierry Lelegard, Paris, FR;
Pascal Junod, Vufflens-la-Ville, CH;
Nagra France SAS, Paris, FR;
Abstract
Example embodiments relate to an encryption and decryption method for a conditional access content, including (a) extracting a marker (Mc) from a data packet (DP); (b) creating a first marking block including the marker (Mc) and a second padding value (PAD); (c) encrypting the first marking block with a second encryption key (K); (d) encrypting a second encrypted marking value (MK) of the first encrypted marking block; (e) creating a mixed marking block including the second encrypted marking value (MK) a the first encrypted padding element (PADK); (f) decrypting the mixed marking block a device of the first encryption key (K), in order to obtain a decrypted mixed marking block; (g) extracting a predetermined part of the decrypted mixed marking block; (h) comparing the extracted part with a reference value (Mc; PDV); and (i) if the comparison leads to an identity, determining a new set of encryption parameters different to the first set of encryption parameters and repeating steps b) to h) in which the second set of encryption parameters is replaced by the new second set of encryption parameters.