Abstract: The method of protection of a microcircuit against an attack includes: a step (205) of determining if an attack has been detected, if an attack has been detected, a step (210, 510) of executing a protection function, and if no attack has been detected, a step (215, 515) of executing a decoy function simulating the protection function and perceptible from outside the microcircuit in a manner substantially identical to the protection function. In some embodiments the decoy function has a power consumption substantially identical to that of the protection function, the protection function effects a step of writing predetermined data at a first address of a non-volatile memory, and the decoy function effects a step of writing in non-volatile memory at a second address different from the first address.

Abstract: The invention relates to a secure data processing method comprising the steps of generating (E204; E304) a first random value (A1); executing (E206; E306) a first cryptographic algorithm (FK) using the first random value (A1); generating (E208; E308) a second random value (A2); executing (E210; E310) a second cryptographic algorithm (FK; GK) using the second random value (A2); and generating a result (V) to verify that the first algorithm (FK) was properly executed.

Abstract: A data processing method comprises the following steps: determining a first result data word from a first input data word and a first secret data word; obtaining a first compressed data word from the first result data word or the first input data word using a compression algorithm; determining a second result data word from a second input data word and a second secret data word; obtaining a second compressed data word from the second result data word using the compression algorithm; comparing the first compressed data word and the second compressed data word.

Abstract: A method for securing a program against attacks by error, i.e. in a chip card, wherein at least one jump instruction, including a relative address chosen from a plurality of possible relative addresses, is identified in the program, wherein the at least one jump instruction makes it possible to reach a targeted address inside the memory area extending before and after the jump instruction and regrouping the plurality of possible relative addresses, inside the memory area, wherein an instruction to be preserved is identified and, in order to secure at least the instruction, at least one first non-operative batch including at least one instruction is inserted, the insertion being carried out in such a way as to ensure that the insertion is compatible with maintenance of the address targeted by the jump instruction inside the memory area and that the insertion is compatible with the normal running of the program.

Abstract: The method of protection of a microcircuit against an attack includes: a step (205) of determining if an attack has been detected, if an attack has been detected, a step (210, 510) of executing a protection function, and if no attack has been detected, a step (215, 515) of executing a decoy function simulating the protection function and perceptible from outside the microcircuit in a manner substantially identical to the protection function. In some embodiments the decoy function has a power consumption substantially identical to that of the protection function, the protection function effects a step of writing predetermined data at a first address of a non-volatile memory, and the decoy function effects a step of writing in non-volatile memory at a second address different from the first address.

Abstract: A secure data processing method includes the following steps: padding (E206) a memory area (MAC?) with a pad value (A); writing (E208) a first datum in the memory area (MAC?); in the area, reading (E210) a second datum with at least one part of the first datum as it was written in the memory area (MAC?); and executing an operation (E210) using the second datum.

Abstract: A data processing method comprises the following steps: determining a first result data word from a first input data word and a first secret data word; obtaining a first compressed data word from the first result data word or the first input data word using a compression algorithm; determining a second result data word from a second input data word and a second secret data word; obtaining a second compressed data word from the second result data word using the compression algorithm; comparing the first compressed data word and the second compressed data word.

Abstract: A method for securing a program against attacks by error, i.e. in a chip card, wherein at least one jump instruction, including a relative address chosen from a plurality of possible relative addresses, is identified in the program, wherein the at least one jump instruction makes it possible to reach a targeted address inside the memory area extending before and after the jump instruction and regrouping the plurality of possible relative addresses, inside the memory area, wherein an instruction to be preserved is identified and, in order to secure at least the instruction, at least one first non-operative batch including at least one instruction is inserted, the insertion being carried out in such a way as to ensure that the insertion is compatible with maintenance of the address targeted by the jump instruction inside the memory area and that the insertion is compatible with the normal running of the program.

Abstract: The invention relates to a secure data processing method comprising the steps of generating (E204; E304) a first random value (A1); executing (E206; E306) a first cryptographic algorithm (FK) using the first random value (A1); generating (E208; E308) a second random value (A2); executing (E210; E310) a second cryptographic algorithm (FK; GK) using the second random value (A2); and generating a result (V) to verify that the first algorithm (FK) was properly executed.

Abstract: A method for making secure execution of a computer program includes the following steps: stacking a predetermined value in a pile of instructions of the program; and stack popping the pile, the stack popping step being adapted, as the case may be, to enable detection of an anomalous execution.