Abstract: The invention concerns a method for authenticating a software downloaded in a terminal, comprising the following steps: authenticating by certificate said downloaded software by means of a software integrated in said terminal; authenticating by certificate, during execution of said downloaded software, said integrated software by means of an authenticating software module associated with said downloaded software.

Abstract: An authentication method provides a segment forming an executable authentication plug-in previously authenticated by at least one authentication function from an authentication library and linked to a plurality of segments in accordance with a chaining relationship. In response to a request for authentication of a plurality of segments chained in accordance with the chaining relationship in this way, the method authenticates each successive segment and, in the case of a segment requiring the authentication plug-in, it executes the authentication plug-in in order to authenticate the segment submitted in this way to the authentication plug-in.

Abstract: A receiver/decoder (for example for digital television) normally receives and/or decodes transmitted data in a normal transmitted signal. In order to test an application running on the receiver/decoder, a special test signal could be generated, or a normal signal could be modified before supply to the receiver/decoder. However, this is costly and complex. To overcome these problems, the receiver/decoder simulates the reception of such transmitted data to produce simulated data; and the application to be tested processes such simulated data in addition to, or instead of, such transmitted data. Simulation may involve generating the simulated data in the receiver/decoder, or controlling the generation of the simulated data by a workstation and receiving the simulated data from the workstation. Data generation may employ a model of the transmitted signal, the model having various parameters which can be varied.

Abstract: The invention concerns a method for authenticating a software downloaded in a terminal, comprising the following steps: authenticating by certificate said downloaded software by means of a software integrated in said terminal; authenticating by certificate, during execution of said downloaded software, said integrated software by means of an authenticating software module associated with said downloaded software.

Abstract: A method of downloading data to a receiver/decoder comprises the steps, at the receiver/decoder, of: receiving a bitstream including the data; downloading a loader for loading the data from the bitstream into the receiver/decoder, and downloading said data from the bitstream using said loader.

Abstract: In a digital satellite television system in which a television receives its signal via receiver/decoder, such as a set top box, interactive applications can be downloaded and run on the receiver/decoder. The application code is arranged as modules, and the downloading of modules is preceded by searching a directory module within a specified local address. The modules are signed and the directory module is signed and encrypted so that a single encryption applies to all of the modules making up the application. Multiple public encryption keys are stored in ROM in the receiver/decoder, so that applications can be created by different sources, without the sources needing to know each other's private encryption keys. A facility is provided to enable an encryption key to be temporarily stored in RAM in the receiver/decoder, so that a manufacturer of the receiver/decoder can check its functionality. A signature of the directory may be hidden at a variable position in a block of dummy data in the directory module.

Abstract: An authentication method provides a segment forming an executable authentication plug-in previously authenticated by at least one authentication function from an authentication library and linked to a plurality of segments in accordance with a chaining relationship. In response to a request for authentication of a plurality of segments chained in accordance with the chaining relationship in this way, the method authenticates each successive segment and, in the case of a segment requiring the authentication plug-in, it executes the authentication plug-in in order to authenticate the segment submitted in this way to the authentication plug-in.

Abstract: A receiver/decoder (for example for digital television) normally receives and/or decodes transmitted data in a normal transmitted signal. In order to test an application running on the receiver/decoder, a special test signal could be generated, or a normal signal could be modified before supply to the receiver/decoder. However, this is costly and complex. To overcome these problems, the receiver/decoder simulates the reception of such transmitted data to produce simulated data; and the application to be tested processes such simulated data in addition to, or instead of, such transmitted data. Simulation may involve generating the simulated data in the receiver/decoder, or controlling the generation of the simulated data by a workstation and receiving the simulated data from the workstation. Data generation may employ a model of the transmitted signal, the model having various parameters which can be varied.

Abstract: A method for downloading an executable application into a decoder for a digital broadcast system, characterized in that the application is stored on a portable memory card introduced into a card reader in the decoder, the decoder reading and downloading the application from the card. Data may be preferably be stored in the smart card in a broadcast data format such as the MPEG format to permit the processing of such data in the same manner as the control unit of the decoder processes data downloading by a broadcast transmission. The invention extends equally to a decoder and a memory card for use in such a method.

Abstract: The invention concerns a method for administrating information in a system for interactive communication comprising :

Abstract: A method for downloading an executable application into a decoder for a digital broadcast system, characterized in that the application is stored on a portable memory card introduced into a card reader in the decoder, the decoder reading and downloading the application from the card. Data may preferably be stored in the smartcard in a broadcast data format such as the MPEG format to permit the processing of such data in the same manner as the control unit of the decoder processes data downloading by a broadcast transmission. The invention extends equally to a decoder and a memory card for use in such a method.