2 METHOD OF TESTING THE RESISTANCE OF A CIRCUIT TO A SIDE CHANNEL ANALYSIS OF SECOND ORDER OR MORE

摘要

The present invention relates to a method to test a circuit. The method includes: a step of obtaining a plurality of value sets including values of physical quantity or logical signal connected with the activity of a circuit to be tested when the circuit executes a task of a password task set applied to confidential data; a step of selecting at least two partial sets of each of the value sets (Ci); a step of counting the frequency of the generation of a value converted by a first surjective function applied to a value (EC1i[j]) of a partial set in regard to each of the partial sets and each of the value sets; a step of forming all available n-tuples connected with the frequency of the generation of the partial sets; a step of calculating a partial task result of each partially available value of the confidential data; a step of calculating accumulated generation frequency sets by adding up generation frequency sets, corresponding to tasks of a task set providing a partial task result having the same conversion value generated with the application of a second surjective function when applied to the same value among the partially available values of the confidential data; and a step of analyzing the accumulated generation frequency sets to determine a part of the confidential data.