Abstract: An access control method is described for an encrypted program transmitted by an operator to a plurality of groups of subscribers, where each group of subscribers has a group key KG, and each subscriber is able to receive from the operator an operating key KT, enciphered by the group key KG for decryption of the transmitted program. The method further involves linking the enciphered operating key KT to a random value R to generate a secret code, transmitting the secret code to subscribers prior to transmission of the encrypted program, and transmitting the random value R to subscribers for calculation of the operating key KT.

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: A method involving a mode for detecting the protocol implemented within and by a portable object. After transmission of a response upon turning on the portable object, an initial signal is received from the interface device. The initial signal is sampled according to at least one of the first and second speeds associated with the first and second respective protocols. In the portable object, at least one sample of a resulting sampling signal is compared to at least one key protocol condition proper to one of the first and second protocols. According to the result of the comparison, the data exchanged according to one of the first or second communication protocols is processed in the portable object.

Abstract: A method of distributing a message from a message administration service to a subscriber receiver decoder of a digital multimedia network comprises transferring a determined message for a determined receiver decoder from the message administration service to a point to point communication system distinct from the multimedia network. A destination point address of a receiver in the point to point communication system is determined, corresponding to the determined receiver decoder. The determined message is buffered in the point to point communication system, and retrieved at the determined receiver decoder from the receiver.

Abstract: A method for securing a portable security module for use with a decoding element, the portable security module and the decoding element allowing to descramble scrambled audiovisual information. The method comprises analyzing at the portable security module a sequence of command messages, the command messages of the sequence being received at the portable security module at distinct times.

Abstract: A digital satellite television system has a plurality of set-top-boxes associated with a plurality of end users' television receivers, a modem and a decoder housed in each STB, a Subscriber Authorization System (SAS) incorporating or having associated therewith a plurality of communication servers, means included in the SAS for generating Electronic Managements Messages (EMM), a back channel interconnecting each of the STBs individually with the SAS, means included in the SAS and each STB so that the necessary information required to inject a relevant EMM into the system is supplied directly to the relevant communication server included in or associated with the SAS to authorize the release of the said EMM and/or means to connect the modem to the back channel and means whereby an EMM is transmissible to the decoder directly from a relevant communication server included in or associated with the SAS. Further important features are also disclosed.

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: A receiver/decoder for use in a digital satellite radio or television system includes a decoder and means to accommodate a credit or bank card carrying a microprocessor, and means to interact with said microprocessor when the credit or bank card is inserted into an operative position in said receiver/decoder in order to enable data carried by said credit or bank card to be read and data to be input to the microprocessor carried by said credit or bank card. A PIN number may be transmitted to the receiver/decoder in a secure fashion by means of a remote controller, which is also described. Applications of the invention include Pay-Per-View television, teleshopping and telebanking.

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: The customizing of a smartcard chip with a complete software begins with masking a smartcard chip by storing a first part of the software. The first part of the software, when executed, is enabled to input unlocking data at an input port of the smartcard chip, to use the unlocking data to decrypt encrypted data stored in the smartcard, and to store the decrypted data in the smartcard memory. Masking of the smartcard chip further comprises storing encrypted customization software. The customization software, when executed, is enabled to input data and to store the input data in the smartcard memory. After decrypting and executing the customization software; the second part of the software is input and stored in the smartcard, enabling the whole software on the smartcard.

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.