Online DB & Software Activation for Desktop App

Question

Hi,

 I have developed an application in c# which runs in windows desktop. I need to have the following feature in it. but I dont know how to do it. please help

 

1. I have an online sql database which doesnt have a secure connection string. I mean connection string includes username & password. How can access an online database with encrypted connection string.

 

2.I want to create a online product activation system using the above mentioned database.  Which the best way to do it.

 

 

NB: My application running in desktop.