The easiest way to configure SSL is to use the configuration application. This is the multi-step wizard which you will have used at the end of the installation process.

If you need to re-run the configuration application, you can do this by using the "Sql Data Catalog Setup" link on the desktop, or run the executable from "C:\Program Files\Red Gate\SQL Data Catalog\ConfigurationApp\RedGate.SqlDataCatalog.ConfigurationApp.exe"

You can then choose "Next" on the license management page which takes you to the SSL page where you can enable or disable the SSL checkbox. For this to take effect you'll then need to go to the next page and re-enter the username and password for the service. When you click "Finish", the service will be reconfigured to either turn SSL on or off depending on the state of the checkbox.

If you turn on SSL then information transferred between the browser and the web application will be fully protected. See this page for information on how Sql Server credentials are handled.