Devices for hiding operations performed in a microprocesser card

摘要

The invention concerns microprocessor cards and, in such cards, various devices for hiding operations performed in the card against fraudulent breaches by analysing the current consumed. The invention is characterised in that it consists in adding in the card a device (20) modifying the consumed current, either by averaging it by integration, or by adding thereto random values by a random signal generator (28) so as to hide the operations performed. In another embodiment, it consists in carrying out simultaneously an operation for making secure and writing in an EEPROM memory, the latter generating chaotic current variations which hide the operation to be made secure.