Abstract: The invention relates to a method of transmitting at least one additional piece of data D in a list of access control words CWi to a scrambled content transmitted by a content server of an operator to a user equipment (2) including a reception terminal (4) associated with a security processor (6), each control word CWi of said list being designed to descramble said contents during a determined cryptoperiod, this method includes the following steps: a) prior replacement of at least one of the control words of said list with a magnitude X resulting from the treatment of said additional piece of data D by a function G having a dual function H, and, at the reception of said list by the 15 reception terminal (4), b) retrieve said additional piece of data D by treating said magnitude X with dual function H.

Abstract: A method for protecting content to be distributed to a pool of receiving terminals connected to a content distribution network and each having a specific security level depending on the technical securing means used, the method comprising the following steps: when sending, generating a key for scrambling said content, transforming said scrambling key using a first calculation module 26 arranged at the headend of said content distribution network, scrambling the content using the transformed key, transmitting the scrambled content and the scrambling key to the terminals, and, upon reception of said content and of the scrambling key by a terminal, transforming said scrambling key using a second calculation module arranged in said terminal, descrambling the content with the transformed scrambling key, the method also characterized by the steps consisting of, when sending, applying to said scrambling key, by means of said first calculation module, a function F defined according to the specific security lev

Abstract: A method for controlling access by a secret key K to a scrambled digital content distributed, along with the security data D(K) calculated on the basis of K, by an operator equipped with a content server and an access-rights server to at least one receiving terminal comprising a plurality of access-control modules, each access-control module implementing a specific technology for determining the secret key K.

Abstract: The invention relates to a method of detecting an abnormal use of a security processor invoked by at least one receiving terminal in order to control access to a scrambled digital content supplied by at least one operator to said receiving terminal. This method comprises the following steps: analysing security processor use during a preset observation period TObs, determining on the basis of said analysis the mean value MECM of the number of invocations per time unit of said security processor during said observation period TObs, comparing said mean value MECM with a preset threshold Smax, and if the value MECM is greater than the threshold Smax, applying to said terminal a sanction whereof the level of severity increases progressively.

Abstract: The invention relates to a method of transmitting at least one additional piece of data D in a list of access control words CWi to a scrambled content transmitted by a content server of an operator to a user equipment (2) including a reception terminal (4) associated with a security processor (6), each control word CWi of said list being designed to descramble said contents during a determined cryptoperiod, this method includes the following steps: a) prior replacement of at least one of the control words of said list with a magnitude X resulting from the treatment of said additional piece of data D by a function G having a dual function H, and, at the reception of said list by the reception terminal (4), b) retrieve said additional piece of data D by treating said magnitude X with dual function H.

Abstract: The invention relates to a method for a beneficiary to acquire a right to use a digital content in a contents distribution system comprising a commercial server (2), a rights server (4) and an operations platform (5) for said content, said platform (5) comprising at least one module (6) to purchase a usage right and at least one module (8) for using the purchased right, said purchase module (6) being capable of communicating with said commercial server (2) through a first application protocol specific to the commercial server (2), and said module (8) for using the purchased right being capable of communicating with said rights server (4) through a second application protocol specific to the rights server (4).

Abstract: The invention relates to a method for assuring security of a commercial transaction between a terminal (24) and a digital contents distribution system, comprising a commercial server (2) and a rights server (4), the said transaction comprising a step consisting of sending an electronic ticket from the commercial server (2) to the terminal (24) to certify the effective purchase of the right to use a content in response to a purchase request. The method according to the invention comprises a preliminary step consisting of inserting at least one identifier of at least one beneficiary of the purchased right into the said ticket.

Abstract: The invention relates to a method for transmitting a message to a reception equipment by an operator, the message containing a description of an action to be executed in the said equipment at a time chosen by the operator. This method comprises the following steps: a—generate the said message as a function of the action to be executed, b—completely or partially encrypt the said message using a secret parameter, c—transmit the encrypted message to the said equipment, d—store the encrypted message in the reception equipment, and, e—at the time chosen by the operator, transmit a description for obtaining the said secret parameter to the reception equipment, and on reception, f—decrypt the encrypted message memorised in the reception equipment using the said secret parameter, g—process the said message so that the said action can be executed.