This secure RDC concept using SSH tunnelling can be applied to MacOSX/Windows/*NIX platform. For simplicity, I use Windows XP Pro as a demo here.
I want to access my XP Pro computer (computer A) at work securely from outside of my company network using my laptop (computer B). My company has a firewall that blocks remote desktop connection on any port. However, my company has an ssh server and port 22 is open on the firewall (most companies have this port open for remote administration) to allow connection from outside to the company network.
Using ssh client on the computer B to connect to your company ssh server and then tunnel remote desktop traffic via this ssh connection. Here is how:
First view the PowerPoint presentation Secure Connection to Your Windows XP Pro Computer Anytime, Anywhere to know the working scenario and the requirement and to understand how it works. If you don't have PowerPoint, click here
Then follow the instructions from my documentation