1. An encryption method comprising: an encryption step of encrypting a code; an encryption result judgment step of judging whether a code, concerning an encrypted object code obtained by encrypting an object code by said encryption step, generates a code of a value within a predetermined range; and an encryption result determination step which, in case said encryption result judgment step identifies that a code of a value within the predetermined range is not generated, determines said encrypted object code as an encryption result of said object code.