Method for protecting a scalar multiplication algorithm against attacks by measurement of current, comprises introduction of random feature which affects method of calculation but not result

摘要

The method comprises a first stage in which a point B on a curve E(K') is calculated. A second stage adds a point randomly selected from a group Z which has a predefined property to produce a new point C on the curve E(K'). Finally a point D is calculated on a curve E(K) equal to pi(C)