Abstract: A method of protection against the copying of digital data stored on an information carrier envisages, on the basis of a first identification of an encryption of the digital data and of a second identification of a watermarking of digital data, the determination of a first mark if it has been possible to identify the encryption and the watermarking. A third identification of a type of the information carrier is followed by the determination of a second mark if it has been possible to determine the first mark and if has been possible to identify a determined type of information carrier. A fourth identification of cryptographic signature data accompanying the digital data is followed by the determination of a third mark if it has been possible to determine the second mark and if it has been possible to identify a cryptographic signature datum. A permission for digital copying of the digital data is delivered if it has been possible to determine the third mark.

Abstract: The invention particularly relates to an electrical device for connection to a predetermined network containing at least one watchdog device. The electrical device comprises configuration means for authorizing its operation in the presence of said watchdog device, where these configuration means are based on the recording of a watchdog device public identifier in storage means of the electrical device; means for identifying at least one watchdog device when the electrical device is connected to any network containing such a watchdog device, and means for disabling the electrical device if the watchdog device identified does not correspond to the watchdog device for which it was configured or if said network does not contain a watchdog device. The invention also concerns an antitheft system and a method for pairing devices.

Abstract: A method of protection against the copying of digital data stored on an information carrier envisages, on the basis of a first identification of an encryption of the digital data and of a second identification of a watermarking of digital data, the determination of a first mark if it has been possible to identify the encryption and the watermarking. A third identification of a type of the information carrier is followed by the determination of a second mark if it has been possible to determine the first mark and if it has been possible to identify a determined type of information carrier. A fourth identification of cryptographic signature data accompanying the digital data is followed by the determination of a third mark if it has been possible to determine the second mark and if it has been possible to identify a cryptographic signature datum. A permission for digital copying of the digital data is delivered if it has been possible to determine the third mark.

Abstract: A method of protection against the copying of digital data stored on an information carrier envisages, on the basis of a first identification of an encryption of the digital data and of a second identification of a watermarking of digital data, the determination of a first mark if it has been possible to identify the encryption and the watermarking. A third identification of a type of the information carrier is followed by the determination of a second mark if it has been possible to determine the first mark and if has been possible to identify a determined type of information carrier. A fourth identification of cryptographic signature data accompanying the digital data is followed by the determination of a third mark if it has been possible to determine the second mark and if it has been possible to identify a cryptographic signature datum.

Abstract: To transmit digital data representing a content from a source to a receiver through a digital communication channel, the data being scrambled by at least one control word, the method includes the following steps. The source generates an encryption key which it stores temporarily. It encrypts the control word with the encryption key and transmits to the receiver the scrambled digital data and the encrypted control word, the latter being transmitted through an encrypted communication channel. The receiver then performs an operation of authentication of the source. When the source is authenticated by the receiver, it transmits the encryption key to it. The receiver then decrypts the control word and descrambles the data so as to present them to a user. The encryption key is then erased from the memories of the source and the receiver when the content has been entirely transmitted.

Abstract: The invention particularly relates to an electrical device for connection to a predetermined network containing at least one watchdog device. The electrical device comprises configuration means for authorising its operation in the presence of said watchdog device, where these configuration means are based on the recording of a watchdog device public identifier in storage means of the electrical device; means for identifying at least one watchdog device when the electrical device is connected to any network containing such a watchdog device, and means for disabling the electrical device if the watchdog device identified does not correspond to the watchdog device for which it was configured or if said network does not contain a watchdog device. The invention also concerns an antitheft system and a method for pairing devices.

Abstract: To transmit digital data representing a content from a source (1) to a receiver (2) through a digital communication channel, the data being scrambled by at least one control word (CW), the method includes the following steps. The source generates an encryption key (KCW) which it stores temporarily. It encrypts the control word with the encryption key and transmits to the receiver the scrambled digital data (3) and the encrypted control word (4), the latter being transmitted through an encrypted communication channel (21). The receiver then performs an operation (22) of authentication of the source. When the source is authenticated by the receiver, it transmits the encryption key (KCW) to it. The receiver then decrypts the control word and descrambles the data so as to present them to a user. The encryption key is then erased from the memories of the source and the receiver when the content has been entirely transmitted.

Abstract: The invention concerns a device for reading digital data (10) receiving data representing a content designed to be connected to a digital home network. It comprises: first means for encrypting (13) data in accordance with a protection mode specific to a line whereby the device is to be connected to another digital network device, the encrypted data being in that case supplied to a first output (S1); and second means for encrypting (14) data in accordance with a mode specific to the home network, the encrypted data being in that case supplied to a second output (S2). The invention also concerns a device for recording and restoring digital data designed to be connected to said reading device (10).

Abstract: A carrier recovery process for a received signal comprises estimating the signal carrier frequency, and estimating the signal phase after frequency estimating. During frequency estimating, signal equalizing is performed, during which an equalizer comprising a direct adaptive filter and a recursive adaptive filter adapts only the coefficients of the recursive adaptive filter. During phase estimating, the equalizer adapts only the coefficients of the recursive adaptive filter for a predetermined time.