1. A method for protecting execution of an algorithm by a processor of an integrated circuit, the algorithm taking into account at least one valid piece of data stored in memory of the integrated circuit and at least one secret key, and performing several iterations of an encryption calculation, the method comprising: executing, by the processor, the algorithm with the valid data stored in the memory between several executions of the same algorithm with false data, wherein the false data comprises a combination of the valid data with predetermined masks, and wherein a position of the execution of the algorithm with the valid data among the several executions of the same algorithm with the false data is randomly selected.