Abstract: A method of secure communication of digital data between devices, including validating, by a security module, the devices using device identifiers, generating a random key in the security module, and transmitting the random key to the devices.

Abstract: The invention concerns a method for verifying television receiver sets with access control and a corresponding receiver set. The invention is characterized in that a broadcaster performs parametered calculations, for example through the subscriptions and the characteristics of the receiver sets. The results of said calculations are transmitted to the receiver set which store them. In order to verify a receiver, the broadcaster transmits thereto the parameter(s) used, the receiver performs the calculation and compares the result it obtains with that which it has stored. In case of non-conformity, the receiver set modifies its operating conditions. The invention is applicable to television with access control.

Abstract: A method for transmitting information between a transmitter station and a plurality of receiving stations in which encrypted information is transmitted from the transmitter station to the receiver station with a first key and at least a control message bearing a second key. The first key used for decryption is restored in each receiving station from the second key and from at least one datum selected from a set of data available in the receiving stations, according to a selection command periodically transmitted between the transmitting station and the receiving station. Such a system may find particular application to pay television.

Abstract: This invention relates to a digital electronic component which is protected against electrical- and/or electromagnetic-type analyse). The inventive component comprises: a synchronous element (10) which is controlled by a clock (H); means (11, 12) of generating said clock (H), the frequency of which varies randomly between a minimum value and a maximum value for at least a given period of time; and means (13) of controlling the random nature of the frequency change of said clock (H).

Abstract: A method of secure communication of digital data between devices, including validating, by a security module, the devices using device identifiers, generating a random key in the security module, and transmitting the random key to the devices.

Abstract: This invention relates to a digital electronic component which is protected against electrical- and/or electromagnetic-type analyses. The inventive component comprises: a synchronous element (10) which is controlled by a clock (H); means (11, 12) of generating said clock (H), the frequency of which varies randomly between a minimum value and a maximum value for at least a given period of time; and means (13) of controlling the random nature of the frequency change of said clock (H).

Abstract: The present invention relates to a method of providing secure communication of information between at least a first and second digital audiovisual device (30, 52) and characterized in that the first device (30) communicates to the second device (52) a certificate Ct(KpubT) comprising a transport public key KpubT encrypted by a management private key KpriMan, the second device (52) decrypting the certificate using an equivalent management public key KpubMan and thereafter using the transport public key KpubT to encrypt information sent to the first device, the first device using an equivalent private key KpriT to decrypt the information. The present invention is particularly applicable to a method of providing secure communication between a first and second decoder.

Abstract: The invention concerns a method for verifying television receiver sets with access control and a corresponding receiver set. The invention is characterized in that a broadcaster performs parametered calculations, for example through the subscriptions and the characteristics of the receiver sets. The results of said calculations are transmitted to the receiver set which store them. In order to verify a receiver, the broadcaster transmits thereto the parameter(s) used, the receiver performs the calculation and compares the result it obtains with that which it has stored. In case of non-conformity, the receiver set modifies its operating conditions. The invention is applicable to television with access control.

Abstract: The present invention relates to a method for transmitting information between a transmitter station (100e) and a plurality of receiving stations (100r) wherein encrypted information is transmitted from the transmitter station to the receiver station with a first key and at least a control message bearing a second key. According to the invention, the first key used for decryption is restored in each receiving station from the second key and from at least one datum selected from a set of data available in the receiving stations, according to a selection command periodically transmitted between the transmitting station and the receiving station.

Abstract: A method and apparatus for the transmission and reception of scrambled data is disclosed. In some embodiments, the method and apparatus includes transmitting a scrambled data stream to a decoder, sending the scrambled data stream to a portable security module inserted in the decoder, descrambling the scrambled data stream, encrypting a descrambled data stream, and using the encrypted data stream to the decoder, decrypting the encrypted data stream, and using the decrypted data stream.

Abstract: A method and apparatus for the transmission and reception of scrambled data is disclosed. In some embodiments, the method and apparatus includes transmitting a scrambled data stream to a decoder, sending the scrambled data stream to a portable security module inserted in the decoder, descrambling the scrambled data stream, encrypting a descrambled data stream, and using the encrypted data stream to the decoder, decrypting the encrypted data stream, and using the decrypted data stream.