Abstract: A coprocessor includes a calculation unit for executing at least one command, and a securization device. The securization device includes an error detection circuit for monitoring the execution of the command so as to detect any execution error, putting the coprocessor into an error mode by default as soon as the execution of the command begins, and lifting the error mode at the end of the execution of the command if no error has been detected, an event detection circuit for monitoring the appearance of at least one event to be detected, and a masking circuit for masking the error mode while the event to be detected does not happen, and declaring the error mode to the outside of the coprocessor if the event to be detected happens while the coprocessor is in the error mode. Application in particular but not exclusively to coprocessors embedded in integrated circuits for smart cards.

Abstract: A countermeasure in a logic circuit having a logic gate supplying a binary output signal, the method including supplying binary data having random values to inputs of logic circuit during a precharge phase; supplying data to process to inputs of the logic circuit during a data processing phase; supplying on input of the logic circuit a precharge command signal launching a precharge phase; and under the effect of the precharge command signal, adapting the functioning of a logic gate of the logic circuit, statistically unbalanced, so that the output signal of the logic gate is in a binary state with a same probability as the random binary data supplied on input of the logic circuit during the precharge phase.

Abstract: A coprocessor includes a calculation unit for executing at least one command, and a securization device. The securization device includes an error detection circuit for monitoring the execution of the command so as to detect any execution error, putting the coprocessor into an error mode by default as soon as the execution of the command begins, and lifting the error mode at the end of the execution of the command if no error has been detected, an event detection circuit for monitoring the appearance of at least one event to be detected, and a masking circuit for masking the error mode while the event to be detected does not happen, and declaring the error mode to the outside of the coprocessor if the event to be detected happens while the coprocessor is in the error mode. Application in particular but not exclusively to coprocessors embedded in integrated circuits for smart cards.

Abstract: A method for monitoring the execution of a sequence of instruction codes in an integrated circuit comprising a central processing unit provided for executing such instruction codes. Current cumulative signatures are produced using deterministic address, control or data logic signals involved in the execution of the sequence and taken off at various points of the integrated circuit. A final cumulative signature is compared with an expected signature and an error signal is produced if the two signatures are not identical. Particularly useful to secure integrated circuits for smart cards.

Abstract: The present invention relates to a coprocessor comprising a calculation unit for executing a command, and a securization device for monitoring the execution of the command and supplying an error signal having an active value as soon as the execution of the command begins and an inactive value at the end of the execution of the command, if no abnormal progress in the execution of the command has been detected. The coprocessor further comprises means for preventing access to at least one unit of the coprocessor, while the error signal is on the active value. Application is provided particularly but not exclusively to the protection of integrated circuits for smart cards against attacks by fault injection.

Abstract: An electronic circuit includes configurable cells each having a test input and an output. The configurable cells are connected to one another in a chain in a predefined order via their test input and their output to form a test register based on receiving a chaining command signal. The electronic circuit also includes a detection circuit activated by the chaining command signal to produce a state signal representing a state of initialization of a first set of configurable cells A multiplexing circuit selectively connects the test input of each configurable cell to a second set of the configurable cells either to the output of a preceding configurable cell or to an output of a decoy data generator based on the state signal.

Abstract: An electronic circuit includes configurable cells capable of being functionally linked to logic cells with which they cooperate to form at least one logic circuit if a chaining command signal is in a first (inactive) state. The electronic circuit also includes a logic interconnection circuit for performing the following functions if the chaining command signal is in a second (active) state. Functionally connecting the configurable cells in a linear feedback shift register if an authentication signal is in a first state, or functionally connecting the configurable cells in a chain in a predefined order to form a shift register if the authentication signal is in a second state.

Abstract: A method for monitoring the execution of a sequence of instruction codes in an integrated circuit comprising a central processing unit provided for executing such instruction codes. Current cumulative signatures are produced using deterministic address, control or data logic signals involved in the execution of the sequence and taken off at various points of the integrated circuit. A final cumulative signature is compared with an expected signature and an error signal is produced if the two signatures are not identical. Particularly useful to secure integrated circuits for smart cards.

Abstract: A method of read or write access by an electronic component of data, including generating a first secret key for a first data of an ordered list of data to access, and for each data of the list, following the first data, generating a distinct secret key by means of a deterministic function applied to a secret key generated for a previous data of the list, and the application of a cryptographic operation to each data to be read or to be written of the list, carried out by using the secret key generated for the data.

Abstract: A circuit for detecting a fault injection in an integrated circuit including: at least one logic block for performing a logic function of said integrated circuit; an isolation block coupled to receive a signal to be processed and an isolation enable signal indicating a functional phase and a detection phase of the logic block, the isolation block applying, during the functional phase, the signal to be processed to at least one input of the logic block, and during the detection phase, a constant value to the input of the logic block; and a detection block adapted to monitor, during the detection phase, the state of the output signal of the logic block, and to generate an alert signal in case of any change in the state of the output signal.

Abstract: A method secures a memory in which individually read-accessible binary words are saved. The method includes defining a memory zone covering a plurality of words, calculating a cumulative signature according to all of the words in the memory zone, and storing the cumulative signature as an expected signature of the memory zone to check the integrity of data read in the memory. The method can be applied to the securing of smart cards.

Abstract: A method and a circuit for detecting a disturbance of a state of at least one first flip-flop from a group of several first flip-flops of an electronic circuit, wherein: the respective outputs of the first flip-flops in the group are, independently from their functional purpose, combined to provide a signal and its inverse, triggering two second flip-flops having data inputs forced to a same state, the respective outputs of the second flip-flops being combined to provide the result of the detection; and a pulse signal comprising a pulse at least for each triggering edge of one of the first flip-flops in the group initializes the second flip-flops.

Abstract: A method reads a datum saved in a memory by selecting an address of the memory in which the datum to be read is saved, reading the datum in the memory at the selected address, saving the datum read in a storage space, and when the memory is not being accessed by a CPU, reading the datum in the memory, reading the datum saved in the storage space, and activating an error signal if the datum read in the memory is different from the datum saved. The method can be applied particularly to the protection of smart card integrated circuits.

Abstract: An electronic circuit, including: a logic circuit having a plurality of logic cells; storage cells able to form a shift register, able to be connected to the logic cells; a connection control module having an input for the reception of an identification key, the module connecting the storage cells so as to form a test shift register when the receive input receives a valid identification key, and the module connecting the storage cells so as to form randomly a diversion circuit when the input does not receive a valid identification key. The invention allows the electronic circuit to be protected against fraudulent access in read or write mode. The invention also relates to a smart card including this electronic circuit.

Abstract: An electronic circuit comprises configurable cells driven by command signals to adopt either a standard mode of operation in which they are integrated into a logic circuit, or a test mode in which they provide information on this logic circuit. The circuit includes a spy circuit capable of detecting an abnormal excitation of certain of the conductors through which the command signals travel, thus preventing fraudulent extraction of data out of the configurable cells. The spy circuit includes a logic combination circuit and a state detection cell.

Abstract: An electronic circuit includes configurable cells with a test input and an output. The configurable cells are capable of being connected to one another in a chain in a predefined order via the test inputs and the outputs to form a test shift register if they receive a chaining command signal. A connection control module disconnects the test input from at least one configurable cell if the connection control module receives an invalid identification key. The connection control module leaves disconnected the test input from the at least one configurable cell, or applies a constant potential on the test input of the at least one configurable cell, or connects the test input of the at least one configurable cell at an output of a random-data generator.

Abstract: A method for detecting a disturbance of the state of a synchronous flip-flop of master-slave type including two bistable circuits in series, in which the bistable circuits are triggered by two first signals different from each other, and the level of an intermediary junction point between the two bistable circuits is compared both to the level present at the input of the master-slave flip-flop and to the level present at the output, which results in two second signals providing an indication as to the presence of a possible disturbance.

Abstract: A method and a circuit for detecting a disturbance of a state of at least one first flip-flop from a group of several first flip-flops of an electronic circuit, wherein: the respective outputs of the first flip-flops in the group are, independently from their functional purpose, combined to provide a signal and its inverse, triggering two second flip-flops having data inputs forced to a same state, the respective outputs of the second flip-flops being combined to provide the result of the detection; and a pulse signal comprising a pulse at least for each triggering edge of one of the first flip-flops in the group initializes the second flip-flops.

Abstract: A method and device detect synchronization errors between logic signals of a group of logic signals. A control word is loaded into a shift register arranged in loop and clocked by resulting logic signals equal to the result of the OR logic function and to the result of the AND logic function applied to the logic signals of the group of logic signals. The value of the control word is monitored as it propagates in the shift register, and a synchronization error signal is sent if the control word changes value. Application in particular for checking the integrity of a clock tree in an integrated circuit.

Abstract: The present disclosure relates to a method for executing, by a processor, a program read in a program memory, comprising steps of: detecting a program memory read address jump; providing prior to a jump address instruction for jumping a program memory read address, an instruction for storing the presence of the jump address instruction; and activating an error signal if an address jump has been detected and if the presence of a jump address instruction has not been stored. The present disclosure also relates to securing integrated circuits.