How do VPNs Work?

Virtual private networks, or VPNs, have been gaining popularity in recent years. This is no doubt due to the rise of several successful businesses that are making VPN services more affordable and accessible than ever before. But what does a VPN actually do and how? And why do more and more people see them as a necessity? Let’s dig into the technical details of VPN technology and hopefully understand what the excitement is all about.

How do VPNs Work? Part 1: Data Encryption

Data encryption is simply a fancy term for hiding information. Encryption is essential for how most people interact with the internet. Anyone who uses internet based communication of any form, whether it’s through Facebook, WhatsApp, or even email, relies on encryption to ensure no one besides the person you’re contacting can see the content of the messages. When you are browsing the internet and interacting with websites, your computer is doing a quite a lot of work in the background. It is communicating with various servers, simultaneously sending and receiving information to maintain the connection. It is as if your computer is messaging the website’s server and requesting that it messages back. While services like Facebook and WhatsApp are pretty reliable when it comes to encrypting communication data, your computer usually isn’t. Your computer’s IP address is readily displayed to the server, and it can use this to determine your general location. This data is used to restrict access to content in certain regions, target advertisements, and plenty more. What a VPN does is prevent this from happening by encrypting all the information your computer sends to the server from the moment it leaves the device, including your IP address. The way this works is through the application of complex mathematics. Essentially, encrypting data means to put it in a form that is unrecognizable from the original, but is easy to read with the right key or cipher. The best example of this is the multiplication of large prime numbers. If you multiply two large prime numbers together, you get a unique large number that cannot be divided evenly by any other combination of whole numbers. If this doesn’t make sense yet, perhaps an example will help. If I ask you to multiply 17 and 23, chances are you could provide an answer very quickly. However if I asked which two whole numbers can be multiplied to get 391, it would take you substantially longer to figure it out. Of course, the math that computers use for this process is massively more complicated, but the idea is fundamentally the same.

How do VPNs Work? Part 2: End-to-end Security

While encryption can be a powerful way to ensure data security, it is sometimes not enough. If someone were to intercept the communication and have the key to unlock it, they could read the information and then pass it along to the intended recipient without anyone knowing about it. This is known as a man-in-the-middle attack, and one of the best ways to prevent it is to use a VPN. A VPN ensures that your information stays protected from the moment it is transmitted to the moment it is received by the server. Then the server’s response to you is also encrypted in the same fashion. The data is then disguised further by being placed inside of another file during transmission through a process called encapsulation. The VPN and the server share a set of instructions called a tunneling protocol which allows the information in the files to be read by the sender and recipient alone. This ensures that any other nefarious individuals who may have an interest in your data can’t read it, even if they were to intercept it before it reached its destination. For this reason, many data security experts encourage people to consistently use a VPN when on a public WiFi network, since it is easy for criminals to spy on users connected to it. This practice of end-to-end encryption is another key part of how VPNs function.

How do VPNs Work? Part 3: Post-transmission Anonymity

Most web-based communications of all types leave some sort of traceable record on the internet. As it is often said, what you put on the internet stays there forever, no matter how hard you may try to remove it. That being said, VPNs provide yet another layer of security by making your data much harder to trace back to you. Once you make a request for a particular web page from your computer, typically the information is sent directly from the internet access point you are connected to, such as a router. When you use the web through a VPN, your requests go through the VPN server before reaching the general internet. That way it looks like the request came from the server rather than your personal computer, making you significantly harder to track.

VPN Applications

Now that you have a general idea of what VPNs do and how, its time to have a look at what uses people have found for them.
Many shows and movies are restricted to different parts of the world. Netflix changes what content is available based on which country you’re in. Certain governments may ban shows or movies, or even entire service platforms within their borders. A VPN can avoid most of this since it hides where your internet connection physically is, allowing you to claim you are somewhere you are not.
A VPN can also avoid bandwidth throttling. Throttling occurs when an internet service provider limits the amount of connection your device is allowed to use at once. This is often done when doing things that require of lot of data to be transferred, such as high definition video streaming. However since a VPN hides your information, the service provider cannot tell if you are doing an activity that warrants throttling.
Finally, a VPN is great for reducing how much you are charged for transportation rentals and tickets. Many companies use search history and location data to estimate how much any visitor to their site is willing to pay for a ticket, and modify the prices that are shown to each individual user. For example if you have been searching for vacation destinations and car rental services in another country, an airline might show you higher prices for flights to that country. They assume you are willing to pay more since it seems like you’ve already decided that you’re taking a trip. This can all be avoided by keeping all your information private with a VPN.