Nagravision S.a.

Christophe Gogniat

Marc Bellocchio

Fabien Gremaud

Henri Kudelski

Olivier Brique

Pascal Fuchs

Michael John Hill

Jimmy Cochard

Nicolas Courtin

The invention aims to provide a method and a system on chip able to detect at once hardware and software errors to prevent manipulations for retrieving cryptographic keys, inserting or suppressing instructions to bypass security processes, modifying programs or memory content etc. The system on chip comprises a core including at least two processors, registers, and a data consistency check module. The core is connected to at least one set of memories containing zones for instructions of a first program and of a second program, said instructions being to be executed respectively by the first and second processor, which respectively produce and store result data into the registers and the memories. The data consistency check module is configured to verify conformity of the produced result data by comparing a test result obtained by carrying out a predetermined function F over one of the first or second result data with the corresponding second or first result data and to continue execution of instructions of each program when the comparison is successful, or stop execution when the comparison shows an error.

Method for checking data consistency in a system on chip

The present invention describes a system and a method for securely loading digital information from an external storage device in a non-trusted environment into a memory module in a trusted environment within a data processing system. A master mode and a service mode are described, the master mode being when the secure loading is requested by a secure processor residing within the trusted environment and the service mode being when the loading is requested by an element which is external to the trusted environment i.e. in the non-trusted environment. The system comprises at least one storage device, one memory module and at least one first processor, and further comprises a memory access controller module connected between the processor and the memory module, and a secure memory management module connected to the processor, the memory module, the storage device and the memory access controller. Requests for data made by either the first processor or the external element are passed to the secure memory management module, which loads the data from the storage device to the memory module and configures the memory access controller such that the processor will have access to the data.

Secure memory management system and method

The present invention describes a system and a method for securely loading digital information from a storage device into a memory module in a data processing system, said data processing system comprising at least one storage device, one memory module and at least one processor, said data processing system further comprising a memory access controller module connected between the processor and the memory module, and a secure memory management module connected to the processor, the memory module, the storage device and the memory access controller. Requests by the processor for data are passed to the secure memory management module, which loads the data from the storage device to the memory module and configures the memory access controller such that the processor will have access to the data.

The aim of the present invention is to propose a method and a device with the aim of avoiding problems which could ensue following the de-synchronization of a program counter during the execution of a program. This aim is achieved by a method for controlling the execution of a program involving separating the program into a number of blocks of instructions and adding an input control section and an output control section to each block. The control sections have conditions for entry to the block and conditions for exit from the block. This can be used to check the validity of the execution of a program by verifying the execution history of the program. Action can be taken in the case that any anomaly is found in the program execution compared to the expected execution.

Method to control the execution of a program by a microcontroller

A method is disclosed for access control to conditional access data in a multimedia unit comprising at least one security module. This process includes: reception by the multimedia unit of a control message ECM containing at least one control word cw; transmission of this message ECM to said security module, this control message being associated to a message decryption right; determination of a validity date of the ECM control message decryption rights associated to said security module; determination of the present date; comparison of the present date with the expiration date of the decryption rights and determination of whether the present date is prior to the expiration date. In the affirmative case, decryption of the control message ECM and sending of the control word cw to the multimedia unit occurs In the negative case, reading of a value contained in a counter of the security module and comparison of this value occurs, to determine whether this value is comprised within a range authorizing decryption. Further, in the affirmative case, modification of the value of the counter according to a pre-established rule, and decryption of the control message ECM and sending of the control word cw to the multimedia unit also occurs. Finally, in the negative case, access to the conditional access data is blocked.

Method for access control to conditional access data

The object of the invention is a method of managing the display of event specifications with conditional access, particularly to display an electronic program guide for Pay-TV. This aim is reached by a method including the following steps:

Growing community of inventors

Romanel-sur-Lausanne, Switzerland

Christophe Gogniat