Is there any way to test this or to verify ?

Hello Eric,

To check if your SQL Server 2005 instance is SSL enabled, go to
- SQL Server Configuration Manager and then go to
- SQL Server 2005 Network Configuration
- Choose your instance from the "Protocols for" list and then go to the
properties of the protocol you use for communication.

In the properties window, can you see Certificate and Flags tabs? If so, is
In the Flags tab, is ForceEncryption option for the Database Engine set to
Yes?

You can check if your SQL Server instance is using Certificates for
communication or not by this way.

For more information, you can check out the following links:
http://support.microsoft.com/kb/316898
http://msdn.microsoft.com/en-us/library/ms189067.aspx
http://technet.microsoft.com/en-us/library/ms191192.aspx