Abstract: Systems and methods for performing cascading dynamic crypto periods are disclosed. In embodiments, a control word and a set of functions is transmitted between a head-end and recipient devices at the beginning of a crypto period. The crypto period is divided into a discrete number of sub-crypto periods. The control word used to encrypt and decrypt the broadcast content is changed during each sub-crypto period. At the end of the first sub-crypto period, a derived control word is generated by passing the original control word to a function in the set of functions in order to generate a derived control word at the first transition between sub-crypto periods. The derived control word is used for encryption and decryption of the broadcasted content during the second sub-crypto period. Upon transitioning to the third sub-control-period, the derived control word is input into another function to produce a second derived control word.

Abstract: Techniques are described herein for securing communications in a television transmission network. A television receiver receives encrypted content from a transmission network and the encrypted content is input into a decryption device. The decryption device decrypts the encrypted content and generates supplemental data in order to pad the size of the decrypted content. The padded content may then be output from the decryption device to other components of the television receiver, for further processing, such as decoding and output to an associated presentation device.

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.