The coding method to which the present invention relates takes into account: a polynomial without square g(x), N0, the smallest integer such that g(x) is a divisor of the polynomial xN0+1; n, an odd multiple of N0; a sequence u of n symbols ui to be coded; and e, a power of 2 different from 1, which is residue of e modulo N0 is equal to 1. It includes: an operation of forming a concatenated sequence uu* (304) consisting successively of the sequence u and a sequence of symbols u* such that u*(x)=u(xe) modulo xn+1, an operation of coding the concatenated sequence uu* (305), including at least one division of the concatenated sequence uu* by the polynomial g(x).