A nontransitory computer readable medium having stored thereon computer executable program, said program [A program for generating an elliptic curve cryptographic parameter, ] comprising a function for causing a computer including a storage device to store information, an output device to output information, and a processing device to perform computation, to operate as an apparatus for generating an elliptic curve cryptographic parameter, wherein the apparatus includes:
- a prime number generation unit for generating a prime number r by using the processing device, and for storing the prime number r generated, in the storage device;
- a group order suitability judgment unit for reading the prime number r generated by the prime number generation unit from the storage device, and for judging whether the prime number r is suitable as a group order of an additive group E(K) composed of points on an elliptic curve E over a finite field K=GF(q) in elliptic curve cryptographic processing, by using the processing device;
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- a group order candidate output unit, when the group order suitability judgment unit judges that the prime number r is suitable as the group order of the additive group E(K) composed of points on the elliptic curve E over the finite field K in elliptic curve cryptographic processing, for reading the prime number r generated by the prime number generation unit from the storage device, and for outputting the prime number r as a group order candidate by using the output device.