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:
Jan. 10, 2017
Filed:
Dec. 16, 2011
Vincent Hamon, Rennes, FR;
Gilles Dubroeucq, Saint Piat, FR;
Vincent Hamon, Rennes, FR;
Gilles Dubroeucq, Saint Piat, FR;
Viaccess, Paris la Defense, FR;
Abstract
A method for transmitting and receiving multimedia content having cryptoperiods scrambled by a control word includes a sender using an operating key and an encryption algorithm in a first virtual mother card to encrypt the control word to obtain a cryptogram, using a syntax constructor also in the first virtual mother card to generate an ECM that incorporates the cryptogram, and transmitting it to a terminal. The terminal receives the ECM and using a syntax analyzer contained in a first virtual daughter card associated with the mother card and uses it to locate a position of the cryptogram CW*t in the ECM. Using an operating key of a decryption algorithm in the daughter card, it then decrypts the cryptogram. Then, using the decrypted control word, it proceeds to descramble the cryptoperiod. Meanwhile, the sender occasionally changes the virtual mother card into a different virtual mother card.