Access the Server Manager and select the server instance from the drop-down list.
Click the Virtual Server Class tab.
Select a class from the drop-down list and click Manage.
The Class Manager page appears.
Choose the Content Mgmt tab.
Select Stronger Ciphers.
Choose to edit:
Select the secret key size restriction:
Enter the file location of the message to reject access.
Click OK.
Click Apply.
Select hard start /restart or dynamically apply
For more information, see Introduction to SSL.