a method for determining a representation of a product of a first element and a second element is disclosed comprising , picking a random value for each pair of a first integer between 1 and d and a second integer greater than the first integer , adding the random value to the product of a first value and a second value , and adding the result of the first addition and the product of the first value and the second value . then summing , for each integer between 1 and d , a product of the first and second values associated with the integer , the random values associated with the pairs of which the first integer is the integer concerned , and the values obtained for the pairs of which the second integer is the integer concerned .