Viaccess

Les Collines De I'arche-tour Opera

Quentin Chieze

Nicolas Pochon

David Leporini

Bruno Tronel

Mathieu Boivin

Mathieu Phirmis

Emmanuel Barau

Olivier Granet

Stephane Lafranchi

Louis Neau

Alain Cuaboz

Stéphane Lafranchi

Alexandre Giard

Matthieu Roger

A Method for supplying protected multimedia content during which a terminal a) acquires a service date from a date server and b) evaluates a temporal criterion of a licence with respect to the last acquired service date. A headend associates with each segment of the multimedia content, its transmission date, and transmits it in a stream together with the segment. The terminal extracts from the stream the date of transmission of the segment, then it compares the extracted transmission date to the last acquired service date. And, only if the extracted transmission date is later than the last acquired service date, acquires it as service date, and uses it as last acquired service date on an execution of the step b) between two successive executions of the step a).

Method for supplying protected multimedia content to a terminal

The invention pertains to a method for transmitting a piece of additional data from a security processor to an external apparatus, in which the transmission of the piece of additional data is done by delaying () the start of a transmission of an information frame from the security processor to the external apparatus by a time lag that is a function of the value of this piece of additional data.

Transmission, reception and identification methods, security processor and information recording medium for said methods

The invention relates to a method of transmitting at least one additional piece of data D in a list of access control words CWto a scrambled content transmitted by a content server of an operator to a user equipment () including a reception terminal () associated with a security processor (), each control word CWof said list being designed to descramble said contents during a determined cryptoperiod,

Method of transmitting an additional piece of data to a reception terminal

Protecting data transmission, either multimedia or a control word, between a security processor and a terminal includes, at the security processor, building a current session key by root key diversification as a function of a parameter transmitted by the terminal, decrypting the data, encrypting it with the session key, and transmitting it, and at the terminal, decrypting it using a secret code to obtain plain data, recording, in advance, secret codes, each enabling decryption of only data encrypted by a corresponding session key obtained by root-key diversification with a parameter, which can be the transmitted parameter, receiving the parameter in a message that also contains the data to be decrypted by the security processor, and in response, selecting, from the secret codes, a code for decrypting the data encrypted with the session key, as a function of the parameter or another parameter in the message.

Protection method, decryption method, recording medium and terminal for said protection method

Growing community of inventors

Paris, France

Quentin Chieze