| 摘要 |
<p>The subject of the invention is a countermeasure method for an electronic component implementing a public-key elliptic curve cryptography algorithm the elliptic curve E of which is defined over a body K, said method comprising an iterative scalar multiplication operation allowing a point [k]P to be obtained from a point P on the curve E and an integer k that must be kept secret, the electrical power consumption of the electronic component depending on the value taken by at least one point, which is said to be critical, used in said operation for iteratively determining the point [k]P. The method comprises: a step (500) of providing at least one power of an element c of K, which element is preset, constant, nonzero and different from one; a step of initialising (501) coordinates of at least one critical point to a preset value; and a step of implementing the operation of scalar multiplication (502), the coordinates associated with at least one critical point being modified in each iteration by multiplying at least one of the coordinates of this point by the at least one power of the element c obtained in the providing step (500).</p> |
