Stmicroelectronics (rousset) Sas

Stmicroelectronics S.a.

Sgs-thomson Microelectronics S.a.

Proton World International N.v.

Stmicroelectronics (grand Ouest) Sas

Pierre Guillemin

Yannick Teglia

William Orlando

Pierre-Yvan Liardet

Michel Bardouillet

Joan Daemen

Claude Anguille

Jean-Marie Bourgeois

Bruno Maurice

Jean-Marie Charreton

Julien Couvrand

A method includes receiving, by a first microprocessor, a request of modification of a content of a first memory of the first microprocessor, the first memory being accessible only by the first microprocessor. The method includes accessing, by the first microprocessor, first data associated with the request and a signature generated from the first data with an asymmetric cipher algorithm. The first data and the signature are available in a second memory of a second microprocessor, and the first data is representative of a modification to be applied to the content of the first memory. The modification is representative of a modification of a set of services exposed by the first microprocessor. The method includes verifying, by the first microprocessor, authenticity of the first data based on the signature; and modifying the content of the first memory according to the first data, the modifying being conditioned by the verifying.

Modification of a memory of a secure microprocessor

A hardware monitor circuit includes an electronic control circuit coupled to a processing unit. The electronic control circuit generates multi-bit protection codes and directs operations of the hardware monitor circuit. A bus interface is coupled to an address bus of the processing unit, and the bus interface passes signals associated with a stack structure of the processing unit. The stack structure is arranged to store the multi-bit protection codes in an internal memory coupled to the processing unit. Comparators in the hardware monitor circuit are arranged to accept values from the internal memory and gating logic coupled to the comparators is arranged to generate an error signal when it detects that an address on the address bus read via the bus interface is equal to an address stored in the internal memory. Upon generating the error signal, the processing unit is placed in a secure mode.

Stack overflow protection by monitoring addresses of a stack of multi-bit protection codes

A first operation of comparison of the first initial operand with the second initial operand uses at least one comparison operator in such a way as to obtain a first final result word. A second operation of comparison of the second initial operand with the first initial operand uses the at least one comparison operator in such a way as to obtain a second final result word. Another operation checks the values of the bits of the two final result words in relation to a part at least of r combinations of reference values taken from possible combinations of values of these two final result words. These reference combinations represent a valid result of comparison of the two operands including an equality, a relationship of inferiority and a relationship of superiority between the two operands.

Secured comparison method of two operands and corresponding device

A method and an element of ciphering by an integrated processor of data to be stored in a memory, including applying a ciphering algorithm which is a function of a key specific to the integrated circuit and of an initialization vector, and of memorizing at least the ciphered data, the initialization vector depending at least on the address of storage of the data in the memory.

Stream ciphering of the content of a memory external to a processor

The invention provides a method for controlling a brushless motor, with windings connected in star (`wye`) formation, including the steps of periodically applying a supply voltage between first and second windings, detecting the presence of a current in a third winding, and an instant of cessation of that current, monitoring the value of a back emf induced in the third winding and detecting a zero crossing point of the back emf, timing a predetermined delay from the zero crossing point, and after the end of the delay, applying the supply voltage to other windings. The invention also provides a method for use with motors having windings connected in delta formation.

Control of a brushless motor

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Marseilles, France

Pierre Guillemin