A random number generating unit generates a random number t. An elliptic curve
setting unit defines an elliptic curve E: y^2=x^3-;3x+t. An elliptic curve finitude
judging unit judges whether orders m1 and m2 of respective elliptic
curves Ep1 and Ep2 produced by reducing the elliptic curve E on a
rational number field modulo primes p1 and p2 are relatively prime.
An elliptic curve order computing unit computes an order of the elliptic curve
E. An elliptic curve condition judging unit judges the security of the elliptic
curve E based on the computed order.
