Protection of chip cards against external attack such as those made using simple or differential power analysis by use of a programmable logic unit that can be given one of a number of different configurations after production

摘要

Method for protecting a logic circuit (11) within a central logic unit (1) against external attacks has the following steps: generation of an instruction within the unit for programming a programmable logic circuit (12); loading of the programmable circuit, in response to the instruction, with a specific programming configuration (C1) from a number of possible configurations (C1-C4); programming of the programmable circuit with the selected configuration. An Independent claim is made for a logic unit with a processor (10), logic circuit (11) and a memory (13) with the logic circuit protected against external attacks by use of a programmable logic circuit. The programmable logic circuit is a field programmable gate array of type EPROM or SRAM.