We have an application that must directly access an MS SQL database. The database is in a remote location. Therefore, at the moment, we use a VPN connection which works fine and appears to be safe. However, setting up a VPN connection for each new client is very troublesome. Changing the application to use API call or anything similar is not possible.
Is there a way to securely open MS SQL server ports to access the MS SQL DB without using VPN? Or any other suggestion to solve that problem?