Patent attributes
A cryptographic calculation is carried out in an electronic component according to a specific cryptographic algorithm including at least one specified non-linear operation on blocks of data of k bits, k being a whole number of more than 2. Several blocks of masked intermediate data of j bits are generated from an initial block of data of k bits, j being a whole number that is smaller than k. Then a non-linear operation S is applied to at least one of the masked intermediate data blocks of j bits with the aid of a substitution table with 2 inputs producing a modified data block of j bits. The modified data block of j bits and at least some of the masked intermediate data blocks of j bits are combined to form a result block of k bits corresponding to the initial data block of k bits by means of a transformation including the specified non linear operation.
