| 摘要 |
The invention relates to a cryptographic method wherein, in order to carry out a fully polynomial division of type Q (x) = [U (x) / N (x)], wherein Q (x), N (x) and U(x) are polynomials, respectively a result, dividend and a divider, multiplication of the two polynomial is carried out followed by displacement of the bits of the result of the multiplication. The following operation is performed on the body of the polynomials Fp[x]: formula (I). The invention also enables more complex operations to be carried out, including modular operations. The invention is an alternative to the Montgomery method and does not need any correction. It is useful, in particular, for cryptographic methods wherein polynomial operations are carried out on the body F2[x]. The invention also relates to an appropriate coprocessor for carrying out said method. Preferred application: chip cards. |
