Abstract: To obtain a remote authentication system that securely authenticates with protecting biometrics information, which is user's personal information, and is firm on security when performing authentication of a person with the biometrics information, and a remote authentication method. The present invention encrypts biometrics information that is user's personal information, and transfers the biometrics information over a network in such a state that only an authentication server, which the user assigns, can decode the biometrics information. Therefore, it is possible to securely protect user's privacy that is the biometrics information in a style of reflecting user's intention, and to prevent reuse of invalid authentication information since it is possible to confirm the date and time, when the authentication information was generated, by the authentication server.