The Danger of Public WIFI Connections
We talk about public WIFI not in order to mention connections in general, since these are a common element in the life of most technology users, but because of their proliferation. They represent a true risk vector for all the information we send and receive on them.
Basically, the concept you have to understand is that any connection to a shared network is usually (if you do not have the appropriate security factors) using the same channel as the other connected users. That is as if you were having a conversation on the same telephone line as all the tenants of your apartment building. By picking up the phone, you could hear what the rest are saying.
To prevent everything that is said to be easily traceable, connections to services use secure protocols (SSL, TLS), but even with these protocols, today there are various ways to skip them and communication is still not private.
Fortunately, there is a way to prevent what we say from ending up in the hands of those who we want the least, even in insecure networks, and that would be a virtual private network.
What is it and why do I need a VPN?
A VPN is a virtual network created above a physical public network (such as the Internet) between two points – our device and a server. The advantage of using a virtual private network is that we can apply the rules to any private network, such as encrypting all point-to-point packages.
The result is a communication that leaves our encrypted computer and that is not decrypted until we reach the VPN server – after having left the WIFI network we were in, having crossed the cables and appropriate switchboards to a server located somewhere in the world.
In addition, VPN is a way to bypass the geographical restrictions of digital services, protect our privacy or possible firewalls that have been enabled in the network of the country or agency where we are or that we want to access (emulate connections from the US to enjoy extra features in services that we usually use such as Netflix, communicate with foreigners over connections monitored by the government, access prohibited content in the office, etc.)
This, therefore, has its drawbacks. VPN connections are usually slower than a direct connection since the information has to be encrypted and decrypted. Also, information has to reach a point which can be thousands of kilometers away and from there it has to be sent to its final destination, which will respond by following the exact same path.
The latter is important since a VPN does not ensure encryption and privacy of data from the sender to the final receiver, but from the sender to the VPN server. After this server, the packets are sent as they have been managed by the client initially (they may be encrypted or not according to the type of connection we establish with the final receiver.)
There have been cases of VPNs that were the cover of a data traffic business, and even some seem to have been controlled by governments and intelligence agencies. As with the nodes that make up the TOR network, it should be understood that the user who uses this type of services can become an interesting target, so it is very important to choose which services to subscribe when you buy a VPN.