Abstract: A system and a method for the creation and transmission of “pre-encrypted” digital content, which is encrypted before being placed on a distributed media transmission server. Preferably a plurality of such servers are used, for example in order to be able to place such a media transmission server in physical proximity to the end user client, whether in terms of geographical proximity or proximity through the network. Use of a plurality of transmission servers also optionally enables the media content to be transmitted flexibly, according to the request of the end user through the end user client.

Abstract: A system and a method for the creation and transmission of “pre-encrypted” digital content, which is encrypted before being placed on a distributed media transmission server. Preferably a plurality of such servers are used, for example in order to be able to place such a media transmission server in physical proximity to the end user client, whether in terms of geographical proximity or proximity through the network. Use of a plurality of transmission servers also optionally enables the media content to be transmitted flexibly, according to the request of the end user through the end user client.

Abstract: A key delivery method for use in an encoded communications system in which at least one encoded item including a first item encoded with a first item control word is sent in a communication stream from a sender to a receiver, the method including transmitting an item entitlement control message (IECM) including item control information, transmitting a stream entitlement control message (SECM) including stream control information, and combining at least part of the item control information and at least part of the stream control information to produce the first item control word. Related methods and apparatus are also disclosed.

Abstract: In a method of receiving packets of data addressed to one or more receivers each having an individual identifier, wherein the data is included in a digital signal having destination addresses successively encrypted from a sequence of control words and receiver identifiers, and control messages containing the control words in encrypted form, address flags and control flags. The method processes the control messages to construct receiver addresses from the control words and the receiver identifier; directs the receiver addresses to update a receiver address register selected by the associated control flag in response to the transmitted control flags; directs each destination address to be compared with the receiver address to one of the address registers selected by the associated address flag in response to the address flags and; accepts each packet of data having a destination address matching the receiver address to which it was compared.