A subscriber's certificate must be revoked in one of the following cases :

• The certificate is no longer used.
• The details of the certificate have changed. For example the subscriber's e-mail address, the subscriber's relationship with the Aristotle University of Thessaloniki PKI, etc.
• The private key has been exposed or there is suspicion that the private key has been exposed.
• The private key has been lost or there is suspicion that the private key has been lost.

After a certificate has been revoked, the certificate is no longer valid. The subscriber must apply for a new certificate.

Subscribers must apply for the revocation of a certificate using the appropriate secure web page.

• User Certificate Revocation.

The appointed server administrator must apply for the revocation of a server certificate using the appropriate secure web page.

• Server Certificate Revocation.

In order to initiate the certificate revocation by a Trusted Third Party which is a holder of the certificate's private key, send your request by e-mail to