ELECTRONIC CERTIFICATE SYSTEM

In order to limit users who can check for validity of a certificate in a system which uses public key certificates, a validity check permit permitting a request to check for validity of the certificate is issued by a permit issuing server 120 to the applicant of the certificate. The certificate applicant sends the validity check permit to a relevant user when the certificate is used (step 701). When having a certificate validity checking server check for validity of the certificate, the user sends the validity check permit of the certificate to be checked to the certificate validity checking server (step 704). The certificate validity checking server verifies the validity check permit (step 706).