1. An addition method for adding a plurality of input binary numbers each of N bits, wherein the method comprises at least one iteration, of index i+1 with i≧0, of an accumulation step enabling an estimation signal U i+1 to be generated on N bits and a first R i+1 or second H i+1 correction signal to be generated on N bits, according to the following equations: { U n i + 1 = U n i ⊕ R n i ⊕ U n - 1 i ⊕ c n R n + 1 i + 1 = ( U n i ⊕ R n i ⊕ U n - 1 i ) · ( U n i ⊕ c n ) or according to the following equations: { U n i + 1 = U n i ⊕ H n i ⊕ c n H n + 1 i + 1 = ( U n i ⊕ H n i ) · ( U n i ⊕ c n _ ) ⊕ c n with: U i+1 n : a value of the bit of rank n of said estimation signal U i+1 , with 0≦n≦N−1, obtained during said iteration of index i+1; U i n : a value of the bit of rank n of an estimation signal U i , obtained during a preceding iteration of index i if i>0, or a determined initialization value U 0 n of the bit of rank n of an estimation signal U i if i=0; U i n−1 : a value of the bit of rank n−1 of said estimation signal U i , obtained during a preceding iteration of index i if n>0 and if i>0, or a determined initialization value U 0 n−1 of the bit of rank n−1 of said estimation signal U i if n>0 and i=0, or a predetermined initialization value of a fictive bit of rank n−1 of said estimation signal U i if n=0; R i n : a value of the bit of rank n of a first correction signal R i , obtained during a preceding iteration of index i if n>0, or a predetermined initialization value of the bit of rank n of said first correction signal R i if n=0; R i+1 n+1 : a value of the bit of rank n+1 of said first correction signal R i+1 , obtained during said iteration of index i+1; H i n : a value of the bit of rank n of a second correction signal H i , obtained during a preceding iteration of index i; H i+1 n+1 : a value of the bit of rank n+1 of said correction signal H i+1 , obtained during said iteration of index i+1; C n : a value of the bit of rank n of an input binary number C included in said plurality of input binary numbers and taken into account in said addition during said iteration of index i+1 of said accumulation step, the estimation signal U i and the first correction signal R i or the second correction signal H i representing a sum of at least two binary numbers in redundant form, the estimation signal U i+1 and the first correction signal R i+1 or the second correction signal H i+1 representing the sum of said at least two binary numbers in redundant form and of the binary number c.