Patent ID: 8559626

Claim:
A sanction server for cryptographic sanctioning of secure transmission of media content from a caching server to at least one client device, the sanction server comprising: a network interface that provides bidirectional data communication with the caching server and the at least one client device via at least one network, wherein the network interface receives a request for the media content from the at least one client device and transmits first sanction data to the caching server and second sanction data to the at least one client device; a random number generator, coupled to the network interface, that generates a random number; a sanction processing module, coupled to the random number generator and the network interface, that, in response to the request for the media content, generates the first sanction data based on the random number and generates the second sanction data based on the random number; wherein the caching server generates first cryptographic data based on the first sanction data and sends the first cryptographic data to the at least one client device; wherein the at least one client device generates second cryptographic data based on the second sanction data and sends the second cryptographic data to the caching server; wherein the caching server generates a scrambling control word for scrambling the media content based on the first sanction data and the second cryptographic data; wherein the at least one client device generates the scrambling control word for descrambling the media content based on the second sanction data and the first cryptographic data; and wherein the first sanction data, the second sanction data, the first cryptographic data and the second cryptographic data are generated in accordance with an asymmetrical public key cryptography algorithm.