You must revoke a certificate if the status of the certificate owner changes or his private key is compromised.
To revoke a certificate:
On the Administration home page, click the Certificate Management tab.
The Certificate Management page appears.
From the Search menu, choose Certificate.
From the other Search menu, choose from the following options:
ID/Serial No. to search by the serial number of the certificate.
Common Name to search by the name of the certificate holder.
In the Search field, enter the serial number or the common name.
Click Go to display the certificate information.
Select the certificate and click View Details to view the certificate.
Click Revoke. A Confirmation screen appears so you can confirm that you are revoking the correct certificate and choose a revocation reason.
Choose a Revocation Reason, and click OK. A message displays confirming that you have revoked the certificate successfully.