Processing method for control messages and security module to carry out said method

Abstract

The present invention concerns a method for processing messages intended to allow the access to conditional access content and to a security module arranged for implementing this method. The method comprises the steps of receiving by a security module comprising at least one decryption module, a plurality of messages, these messages belonging to at least two different categories; assigning a different priority level to messages from each different category, one of said priority level being defined as high and another priority level, lower that the high priority level, being defined as the standard priority level; associating a value to the messages to which the standard priority level has been assigned; assigning at least one threshold value for the value associated with messages having a standard priority level; and comparing between the threshold value for a determined message and the value associated with said message. If no value associated with said message having standard priority level exceeds the corresponding threshold value, processing the messages according to their priority level, a message to which the high priority level has been assigned being processed before a message to which a lower priority level has been assigned, and change of the value associated with the messages having a standard priority level according to said predefined rule. If the value associated with one of said messages having a standard priority level exceeds the threshold value for the corresponding message, processing one of the messages having a standard priority level before processing a message having a higher priority level, and change of the value associated with the messages having a standard priority level according to said predefined rule.

The invention claimed is: 
     
       1. A method for processing messages intended to allow the access to conditional access content, wherein said method comprises:
 receivinga plurality of messages, by a security module comprising at least one conditional access module (CAK) and a processing module, wherein the plurality of messages are classified as a first message belonging to at least one of a first category and a second message belonging to a second category, wherein the first category is different from the second category; 
 assigning a different high priority level to individual messages of the plurality of messages based at least upon the classification, wherein messages classified as belonging to the first category are assigned a high priority level, and messages classified as belonging to the second category are assigned a standard priority level the first messsage and a standard priority level to the second message; 
 associating at least one value with at least one of the messages assigned the standard priority level the second message, wherein the at least one value is generated based at least upon a predefined rule; 
 determining a threshold value for the messages assigned the standard priority level second message; 
 when the at least one value associated with the messages assigned the standard priority level does not exceed second message is equal to or less than the threshold value:
 processing the plurality of messages first message and the second message according to their priority level such that a the first message assigned the high priority level is processed before the messages assigned the standard priority level second message; and 
 changing the at least one value associated with the messages assigned the standard priority level second message according to the predefined rule; and 
 
 when the at least one value associated with the messages assigned the standard priority level second message exceeds the threshold value:
 processing a the second message assigned standard priority level before processing the messages assigned to the high priority level first message; and 
 changing the at least one value associated with the messages assigned the standard priority level second message according to the predefined rule. 
 
 
     
     
       2. The method of  claim 1 , wherein the predefined rule comprises assigning an initial value during the reception of a message by the security module and modifying the initial value associated with the message after processing each message of the plurality of messages the first message and the second message. 
     
     
       3. The method of  claim 1 , wherein the threshold value is a predetermined integer, and wherein the threshold value is exceeded when a value associated with a specific message is higher than the threshold value. 
     
     
       4. The method of  claim 1 , wherein the threshold value is a threshold duration, and wherein the threshold value is exceeded when a value associated with a specific message is higher than the threshold value. 
     
     
       5. The method of  claim 1 , wherein the threshold value is a duration and the threshold value is exceeded when a remaining time (RT) for a specific message is smaller than the threshold value. 
     
     
       6. The method of  claim 2 , wherein assigning the initial value comprises assigning a null value to the message. 
     
     
       7. The method of  claim 2 , wherein assigning an initial value comprises assigning a value higher than a maximum value associated with the messages assigned the standard priority level second message. 
     
     
       8. The method of  claim 2 , wherein modifying the initial value associated with the message comprises incrementing the initial value. 
     
     
       9. The method of  claim 2 , wherein modifying the initial value associated to the message comprises decrementing the initial value. 
     
     
       10. The method of  claim 7 , wherein the difference between the initial value assigned to the message during its reception and the maximum value associated with the messages assigned standard priority level second message is one unit. 
     
     
       11. The method of  claim 8 , wherein the initial value is incremented by one unit. 
     
     
       12. The method of  claim 8 , wherein the initial value is incremented by a value corresponding to a duration for processing a last processed message. 
     
     
       13. The method of  claim 9 , wherein the initial value is decremented by a value corresponding to a duration for processing a last processed message. 
     
     
       14. The method of  claim 4 , wherein the value associated with the specific message is equal to a remaining time (RT), and wherein the remaining time equals:
   RT=TV−AWT
 
 wherein TV is the threshold value; and 
 AWT is an actual duration spent by the specific message in a memory cooperating with the security module. 
 
     
     
       15. A system comprising:
 at least one processor; and 
 memory encoding computer executable instructions that, when executed by the at least one processor, perform a method comprising:
 receivinga plurality of messages, by a security module comprising at least one conditional access module (CAK) and a processing module, wherein the plurality of messages are classified as a first message belonging to at least one of a first category and a second message belonging to a second category, wherein the first category is different from the second category; 
 
 assigning a different high priority level to individual messages of the plurality of messages based at least upon the classification, wherein messages classified as belonging to the first category are assigned a high priority level, and messages classified as belonging to the second category are assigned a standard priority level the first message and a standard priority level to the second message; 
 associating at least one value with at least one of messages assigned the standard priority level the second message, wherein the at least one value is generated based at least upon a predefined rule; 
 determining a threshold value for the messages assigned the standard priority level second message; 
 when the at least one value associated with the messages assigned the standard priority level does not exceed second message is equal to or less than the threshold value:
 processing the plurality of messages first message and the second message according to their priority level such that a the first message assigned the high priority level is processed before the messages assigned the standard priority level second message; and 
 changing the at least one value associated with the messages assigned the standard priority level second message according to the predefined rule; and 
 
 when the at least one value associated with the messages assigned the standard priority level second message exceeds the threshold value:
 processing a the second message assigned standard priority level before processing the messages assigned to the high priority level first message; and 
 changing the at least one value associated with the messages assigned the standard priority level second message according to the predefined rule. 
 
 
     
     
       16. The system of  claim 15 , wherein the predefined rule comprises assigning an initial value during the reception of a message and modifying the initial value associated with the message after processing each message of the plurality of messages the first message and the second message. 
     
     
       17. The system of  claim 16 , wherein modifying the initial value associated with the message comprises incrementing the initial value. 
     
     
       18. The system of  claim 16 , wherein modifying the initial value associated the message comprises decrementing the initial value. 
     
     
       19. The system of  claim 17 , wherein the initial value is incremented by a value corresponding to a duration for processing a last processed message. 
     
     
       20. The system of  claim 18 , wherein the initial value is decremented by a value corresponding to a duration for processing a last processed message. 
     
     
       21. A receiver multimedia unit comprising:
 a receiver, the receiver being configured to receive one or more streams of encrypted content;  
 at least one processor; and 
 memory encoding computer executable instructions that, when executed by the at least one processor, perform a method cause the processor to perform operations comprising:
 receiving a plurality of messagesreceive by a security module comprising at least one conditional access module (CAK) and a processing module, wherein the plurality of messages are classified as a first message belonging to at least one of a first category and a second message belonging to a second category, wherein the first category is different from the second category, and wherein the first message and the second message are associated with at least one stream of the one or more streams of encrypted content; 
 assigningassign a differenthigh priority level to individual messages of the plurality of messages based at least upon the classification, wherein messages classified as belonging to the first category are assigned a high priority level, and messages classified as belonging to the second category are assigned a standard priority levelthe first message and a standard priority level to the second message; 
 
 associatingassociate at least one value with at least one of the messages assigned the standard priority levelthe second message, wherein the at least one value is generated based at least upon a predefined rule; 
 determiningdetermine a threshold value for the messages assigned the standard priority levelsecond message; 
 when the at least one value associated with the messages assigned the standard priority level does not exceed second message is equal to or less than the threshold value:
 processingprocess the plurality of messagesfirst message and the second message according to their priority level such that athe first message assigned the high priority level is processed before the messages assigned the standard priority level second message; and 
 changingchange the at least one value associated with the messages assigned the standard priority levelsecond message according to the predefined rule; and 
 
 when the at least one value associated with the messages assigned the standard priority level second message exceeds the threshold value:
 processing aprocess the second message assigned standard priority level before processing the messages assigned to the high priority level first message; and 
 changingchange the at least one value associated with the messages assigned the standard priority levelsecond message according to the predefined rule.