Establishing Secure Tunnels Using SSL

Now that we understand what SSL is and how it works, let us discuss how SSL allows us to create tunnels.

Secure Tunnels

A secure tunnel between computers can best be understood as a secure channel of communication between two machines that have an insecure environment between them. The communications tunnel is like a tunnel under a river that allows automobiles to travel from point A on one side of the river to point B on the other side and prevents environmental elements like water from interfering with the traffic as shown in the following diagram:

The communications tunnel allows communications between two computers over public networks securely so that other computers on those networks cannot access the communications between the two machines.

However, unlike the example of the tunnel under the river, network tunneling does not employ a physical barrier between the two computers communicating and other machines. Rather, computer-related tunneling involves...