A method for executing by a circuit (CT1, CT2, CT3) a requested operation (OPR, XG5, XG12) whereby a first input data is combined with a second input data, the method comprising: computing a first input set comprising the first input data, by applying Exclusive OR operations (⊕) to the first input data and to all first mask parameters (U) in a first mask set, characterized in that it comprises: generating a second mask set comprising second mask parameters (V), each first mask parameter (U) in the first mask set forming a respective mask pair (U, V) with a corresponding second mask parameter in the second mask set, the mask pairs being such that combinations by XOR operations of the first mask parameter with the second mask parameter in each mask pair produce a third mask set comprising third mask parameters, the mask parameters in each of the first, second and third mask sets being such that each mask parameter in the mask set comprises at least one first word, the first words in the mask set having a same size and forming a word subset comprising a single word from each mask parameter in the mask set and a same number of occurrences of all possible values of a word having the size of the first words; computing a second input set comprising the second input data, by applying XOR operations to the second input data and to all second mask parameters in the second mask set, each data in the first input set being associated with a respective data in the second input set in a respective input pair, such that the mask parameters from which each data in each input pair is computed are associated by one of the mask pairs; applying the requested operation to each input pair to compute output data (PR1[..], PX2<r>, PY7<r>); and providing an output set (PR1, PX2<r>, PY7<r>) of the requested operation comprising all the computed output data. computing a first input set comprising the first input data, by applying Exclusive OR operations (⊕) to the first input data and to all first mask parameters (U) in a first mask set, characterized in that it comprises: generating a second mask set comprising second mask parameters (V), each first mask parameter (U) in the first mask set forming a respective mask pair (U, V) with a corresponding second mask parameter in the second mask set, the mask pairs being such that combinations by XOR operations of the first mask parameter with the second mask parameter in each mask pair produce a third mask set comprising third mask parameters, the mask parameters in each of the first, second and third mask sets being such that each mask parameter in the mask set comprises at least one first word, the first words in the mask set having a same size and forming a word subset comprising a single word from each mask parameter in the mask set and a same number of occurrences of all possible values of a word having the size of the first words; computing a second input set comprising the second input data, by applying XOR operations to the second input data and to all second mask parameters in the second mask set, each data in the first input set being associated with a respective data in the second input set in a respective input pair, such that the mask parameters from which each data in each input pair is computed are associated by one of the mask pairs; applying the requested operation to each input pair to compute output data (PR1[..], PX2<r>, PY7<r>); and providing an output set (PR1, PX2<r>, PY7<r>) of the requested operation comprising all the computed output data. generating a second mask set comprising second mask parameters (V), each first mask parameter (U) in the first mask set forming a respective mask pair (U, V) with a corresponding second mask parameter in the second mask set, the mask pairs being such that combinations by XOR operations of the first mask parameter with the second mask parameter in each mask pair produce a third mask set comprising third mask parameters, the mask parameters in each of the first, second and third mask sets being such that each mask parameter in the mask set comprises at least one first word, the first words in the mask set having a same size and forming a word subset comprising a single word from each mask parameter in the mask set and a same number of occurrences of all possible values of a word having the size of the first words; computing a second input set comprising the second input data, by applying XOR operations to the second input data and to all second mask parameters in the second mask set, each data in the first input set being associated with a respective data in the second input set in a respective input pair, such that the mask parameters from which each data in each input pair is computed are associated by one of the mask pairs; applying the requested operation to each input pair to compute output data (PR1[..], PX2<r>, PY7<r>); and providing an output set (PR1, PX2<r>, PY7<r>) of the requested operation comprising all the computed output data.