MONTGOMERY POWER LADDER ALGORITHM INCLUDING COUNTERMEASURE AGAINST DIFFERENTIAL FAULT ANALYSIS

摘要

A Montgomery power ladder algorithm that provides a countermeasure against a differential fault analysis (DFA) includes an initialization operation and a repetitive arithmetic operation. In the initialization operation, an initial value of a variable i, which will be used in the repetitive arithmetic operation, is set, a basic point P on an elliptic curve and a scalar k are received, and at least two variables are initialized using the basic point P. In the repetitive arithmetic operation, a value Q is computed by multiplying the scalar k by the basic point P by using the two variables, whether a fault was induced during the multiplication is determined by determining the relationship between the two variables and the basic point P, and the value Q or a warning signal STOP is output according to the determination result.