Digital content access control

Abstract

Control of access to at least one digital content is managed as a function of at least one access criterion. The digital content is transmitted to at least one terminal in the form a data stream. The access criterion is stored in the terminal as a function of an identifier. The terminal receives the data stream in association with a control message indicating the identifier. It then retrieves the stored access criterion as a function of the identifier received in the control message. Finally, it verifies whether the stored access criterion is satisfied in order, where appropriate, to authorize access to the content.

1 - 13 . (canceled) 
     
     
         14 : A method of managing control of access to at least one digital content as a function of at least one access entitlement and at least one access criterion, said digital content being transmitted to at least one terminal in the form of an encrypted data stream, wherein said access entitlement is previously stored in memory in the terminal, said access criterion being in association with an identifier, said identifier being a pointer to said access criterion, said method comprising the following step executed in a data stream transmission entity:
 transmitting to the terminal the encrypted data stream in association with a control message transmitting said identifier as provision for controlling access to the digital content, wherein said identifier is the only provision for controlling access to the digital content transmitted in association with the encrypted data stream.   
     
     
         15 : The method of managing control of access according to  claim 14 , wherein the control message further indicates an encryption key for said digital content transmitted in the form of an encrypted data stream. 
     
     
         16 : The method of managing control of access according to  claim 14 , wherein the identifier is transmitted synchronously with the encrypted data stream in a message of the Entitlement Control Message (ECM) type. 
     
     
         17 : A method of managing control of access to at least one digital content as a function of at least one access entitlement and at least one access criterion, said digital content being intended to be transmitted to at least one terminal in the form of an encrypted data stream, wherein said access entitlement is stored in memory in the terminal, said method comprising the following step executed in an access control management entity:
 transmitting an initial message to the terminal, said initial message transmitting an association of an identifier and an access criterion, in order for said access criterion to be stored in association with the identifier, said identifier being a pointer to said access criterion, wherein said identifier is the only provision for controlling access to the digital content intended to be transmitted in association with the encrypted data stream.   
     
     
         18 : The method of managing control of access according to  claim 17 , wherein the association of the identifier and said access criterion is transmitted in a message of the Entitlement Management Message (EMM) type. 
     
     
         19 : An entity for managing control of access to at least one digital content as a function of at least one access entitlement and at least one access criterion, said digital content being intended to be transmitted to at least one terminal in the form of an encrypted data stream, wherein said access entitlement is previously stored in memory in the terminal, said access control management entity comprising a transmission unit adapted to transmit an initial message to the terminal, said initial message transmitting an association of an identifier and said access criterion, in order for said access criterion to be in association with the identifier, said identifier being a pointer to said access criterion,
 wherein said identifier is the only provision for controlling access to the digital content intended to be transmitted in association with the encrypted data stream.   
     
     
         20 : A digital content transmission entity subject to access control in a terminal as a function of at least one access entitlement and at least one access criterion, said digital content being transmitted to at least one terminal in the form of an encrypted data stream, wherein said access entitlement is previously stored in memory in the terminal, said access criterion being in association with an identifier, said identifier being a pointer to said access criterion, said digital content transmission entity comprising a transmission unit adapted to transmit the encrypted data stream in association with a control message transmitting said identifier as provision for controlling access to the digital content, wherein said identifier is the only provision for controlling access to the digital content transmitted in association with the encrypted data stream. 
     
     
         21 : The digital content transmission entity according to  claim 20 , wherein the control message further indicates an encryption key for said digital content transmitted in the form of an encrypted data stream. 
     
     
         22 : The digital content transmission entity according to  claim 20 , wherein the identifier is transmitted synchronously with the encrypted data stream in a message of the Entitlement Control Message (ECM) type. 
     
     
         23 : A system for controlling access to a digital content as a function of at least one access entitlement and at least one access criterion, said digital content being intended to be transmitted to at least one terminal in the form of an encrypted data stream, wherein said access entitlement is previously stored in memory in the terminal, the system comprising:
 an access control management entity comprising a transmission unit adapted to transmit an initial message to the terminal, said initial message transmitting an association of an identifier and said access criterion, in order for said access criterion to be in association with the identifier, said identifier being a pointer to said access criterion;   a digital content transmission entity comprising a transmission unit adapted to transmit the encrypted data stream in association with a control message transmitting said identifier as provision for controlling access to the digital content, and   wherein said identifier is the only provision for controlling access to the digital content transmitted in association with the encrypted data stream.   
     
     
         24 : The system for controlling access to a digital content according to  claim 23 , wherein the system further comprising at least one terminal subject to access the digital content based on at least one access entitlement and at least one access criterion, said digital content being received by the terminal in the form of an encrypted data stream, said terminal comprising:
 a memory to store in memory said access entitlement and an association between an identifier and said access criterion, said identifier being a pointer to said access criterion; a receiver unit to receive the encrypted data stream in association with a control message transmitting said identifier as provision for controlling access to the digital content;   
       a memory management unit adapted to retrieve the stored access criterion as a function of the identifier received in the control message; and 
       a decision unit adapted to verify whether the stored access entitlement enables decryption of the encrypted data stream and whether the retrieved access criterion is satisfied and, where appropriate, to authorize access to the digital content received in the data stream. 
     
     
         25 : The system for controlling access to a digital content according to  claim 23 , wherein the association of the identifier and said access criterion is transmitted in a message of the Entitlement Management Message (EMM) type. 
     
     
         26 : The system for controlling access to a digital content according to  claim 23 , wherein the control message further indicates an encryption key for said digital content transmitted in the form of an encrypted data stream. 
     
     
         27 : The system for controlling access to a digital content according to  claim 23 , wherein the identifier is transmitted synchronously with the encrypted data stream in a message of the Entitlement Control Message (ECM) type.