Cryptographic processing method comprising determining, in a group of finite order provided with an operation and from a first element of this group, a second element (S p; P) which is equal to the combination, by means of said operation, of elements which are equal to the first element and which are equal in number to a first number (d p), the method being implemented within an electronic device comprising a storage module, the first number (d p) being stored in the storage module in masked form, the method being characterized by the following steps: - obtaining (E10; E32) a second number (d") determined by adding said order or a multiple of said order to the first number (d p); - determining (E12; E30) a random number (a); - determining (E14; E34) a quotient (Q; q) and a remainder (R; r) using the Euclidean division of the second number (d") by the random number (a); - obtaining (E16; E36) a third element (E 1; I) which is equal to the combination, by means of said operation, of elements which are equal to the first element and which are equal in number to the product of the quotient (Q; q) and the random number (a); - obtaining (E18; E38) a fourth element (E 2; J) which is equal to the combination, by means of said operation, of elements which are equal to the first element and which are equal in number to the remainder (R; r); - determining (E20; E40) the second element (S p; P) by combining the third element (E 1; I) and the fourth element (E 2; J) by means of said operation, the method comprising a step of constructing a mask which is equal to the sum of a first intermediate number and the product of a second intermediate number and said random number; wherein the step of obtaining the second number (d") comprises a step of applying the constructed mask, wherein the quotient (Q; q) is determined using the second intermediate number and wherein the remainder (R; r) is determined using the first intermediate number. - obtaining (E10; E32) a second number (d") determined by adding said order or a multiple of said order to the first number (d p); - determining (E12; E30) a random number (a); - determining (E14; E34) a quotient (Q; q) and a remainder (R; r) using the Euclidean division of the second number (d") by the random number (a); - obtaining (E16; E36) a third element (E 1; I) which is equal to the combination, by means of said operation, of elements which are equal to the first element and which are equal in number to the product of the quotient (Q; q) and the random number (a); - obtaining (E18; E38) a fourth element (E 2; J) which is equal to the combination, by means of said operation, of elements which are equal to the first element and which are equal in number to the remainder (R; r); - determining (E20; E40) the second element (S p; P) by combining the third element (E 1; I) and the fourth element (E 2; J) by means of said operation, the method comprising a step of constructing a mask which is equal to the sum of a first intermediate number and the product of a second intermediate number and said random number; wherein the step of obtaining the second number (d") comprises a step of applying the constructed mask, wherein the quotient (Q; q) is determined using the second intermediate number and wherein the remainder (R; r) is determined using the first intermediate number. the method comprising a step of constructing a mask which is equal to the sum of a first intermediate number and the product of a second intermediate number and said random number; wherein the step of obtaining the second number (d") comprises a step of applying the constructed mask, wherein the quotient (Q; q) is determined using the second intermediate number and wherein the remainder (R; r) is determined using the first intermediate number.