Device and method for selectively supplying access to a service encrypted using a control word, and smart card
AssigneeIrdeto Eindhoven B.V.
InventorRobert Schipper
Life of this patent
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Abstract
Device (120), smart card (300) and method for selectively supplying access to a service (202) encrypted using a control word. A service (202) is received with an entitlement control message (ECM) (203) comprising authorization data and a specifier of a validity period of the authorization data. The service is decrypted only if the ECM (203) is found valid. The service (202) can be stored on a storage medium such as a DVD. An ECM transcoding module (211) obtains the authorization data from the ECM (203) supplies to writing means (215) a device-specific ECM comprising the authorization data. The device-specific ECM may be encrypted with a key specific to the device (120) and/or comprise an identifier for the device (120).
Claims9
A device for selectively supplying access to a service encrypted using a control word, comprising
- receiving means for receiving the service and an entitlement control message (ECM) comprising authorization data and a specifier of a validity period of the authorization data,
- decrypting means for decrypting the service using the control word,
- a timer for providing a time, and
- conditional access means for obtaining the authorization data and the specifier of the validity period of the authorization data from the ECM and providing the control word to the decrypting means in dependence on a verification of the authorization data and on a determination of the time being within the validity period, characterized by
- ECM transcoding means for obtaining the authorization data from the ECM and for supplying to writing means a device-specific ECM comprising the authorization data.
A method of selectively supplying access to a service encrypted using a control word, comprising
- receiving the service and an entitlement control message (ECM) comprising authorization data and a specifier of a validity period of the authorization data,
- providing the control word in dependence on a verification of the authorization data and on a determination of the time being within the validity period obtained from the CM, and
- decrypting the service using the control word, characterized by obtaining the authorization data from the ECM and for supplying to writing means a device-specific ECM comprising the authorization data.
Dependencies are inferred from the claim text.