The security message is
related to a public key, which is needed in order to authenticate. You
can remove this notification by installing the public key to your local machine.
This process will also help when connecting from home.
To install the public key,
click on the following link public
key. You will see the following
screen:

At this point you can either save the file to your computer by selecting the save button or simply selecting the open button to begin the installation process. If you save the file to your computer you will have to double click on the downloaded file to start the installation.
Once you have selected open or you have double clicked on the downloaded file, you should see the screen prompting you to install the certificate:

Select the install certificate button.
The installation process now begins. When prompted, choose next. The next question will be related to the certificate
store. Simply accept the default
answer and select the next button.

Continue with the installation accepting the default answers until the installation has finished