Global conditional access system for broadcast services
First Claim
Patent Images
1. A method for managing access to a scrambled event of a service provider, said method comprising:
- receiving in a device an electronic list of events available from one or more sources, each event having a digital signature and an encrypted message associated therewith;
receiving in the device, in response to user selection of one of the events from the list of events, the digital signature and the encrypted message associated with the selected event, the digital signature being encrypted with a first key and the encrypted message being encrypted with a second key different from the first key, the encrypted message comprising a descrambling key and event information including at least one of a channel identity, date and time stamp, event identity and payment amount corresponding to the selected event;
authenticating in the device a source of the digital signature and the encrypted message associated with the selected event by decrypting the digital signature in response to receiving the digital signature and the encrypted message;
decrypting in the device the encrypted message to obtain the descrambling key upon the authenticating;
receiving in the device the selected event from the service provider, the selected event being scrambled using the descrambling key for preventing unauthorized access to the selected event; and
descrambling in the device the selected event using the descrambling key.
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Abstract
A method for managing access to a scrambled event, selected from an electronic program guide, of a service provider (including broadcast television networks, cable television networks, digital satellite systems, and internet service providers). Access to the event is only achieved if the descrambling key is obtained from a digitally signed message associated with the event in the electronic program guide. Authentication of the electronic program guide provider involves decrypting the digital signature using a public key of the guide provider.
36 Citations
20 Claims
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1. A method for managing access to a scrambled event of a service provider, said method comprising:
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receiving in a device an electronic list of events available from one or more sources, each event having a digital signature and an encrypted message associated therewith; receiving in the device, in response to user selection of one of the events from the list of events, the digital signature and the encrypted message associated with the selected event, the digital signature being encrypted with a first key and the encrypted message being encrypted with a second key different from the first key, the encrypted message comprising a descrambling key and event information including at least one of a channel identity, date and time stamp, event identity and payment amount corresponding to the selected event; authenticating in the device a source of the digital signature and the encrypted message associated with the selected event by decrypting the digital signature in response to receiving the digital signature and the encrypted message; decrypting in the device the encrypted message to obtain the descrambling key upon the authenticating; receiving in the device the selected event from the service provider, the selected event being scrambled using the descrambling key for preventing unauthorized access to the selected event; and descrambling in the device the selected event using the descrambling key. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method for managing access between a device having a smart card coupled thereto and a service provider, the device performing the steps of:
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receiving an electronic program guide having a plurality of events from a guide provider, the guide having a message and a digital signature associated with each event in the guide, the message being encrypted using a public key of the smart card and the digital signature being created using a private key of the guide provider; selecting an event from the guide; receiving the encrypted message and the digital signature corresponding to the selected event; authenticating the guide provider by decrypting the digital signature using a public key of the guide provider, the guide provider public key being stored in the device; passing the message to the smart card; decrypting, in the smart card, the message using a private key of the smart card to obtain event information and a symmetric key, the smart card private key being stored within the smart card; storing the event information in the smart card and updating account information based on the event information; receiving from the service provider the selected event, the selected event being scrambled using the symmetric key; and descrambling, in the smart card, the selected event using the symmetric key to generate a descrambled event. - View Dependent Claims (16, 17)
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18. A method for managing access between a device having a smart card coupled thereto and a service provider, the device performing the steps of:
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receiving an electronic program guide having a plurality of events from a guide provider, the guide having a digital certificate and a separate message corresponding to each event in the guide, each of said digital certificates being encrypted using a first private key of the guide, the separate message being encrypted using a public key of the smart card and having an associated digital signature created using a second private key of the guide; selecting an event from the guide; receiving the digital certificate, the message and the digital signature corresponding to the selected event; authenticating the guide provider by decrypting the digital certificate using a first public key of the guide to obtain a second public key of the guide, and decrypting the digital signature using the second guide public key, said first guide public key being stored in the device; passing the message to the smart card; decrypting, in the smart card, the message using a private key of the smart card to obtain event information and a symmetric key, the smart card private key being stored within the smart card; storing the event information in the smart card and updating account information based on the event information; receiving from the service provider the selected event, the selected event being scrambled using the symmetric key; and descrambling, in the smart card, the selected event using the symmetric key to generate a descrambled event. - View Dependent Claims (19, 20)
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Specification