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How does a VPN work?

How does a VPN work?
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Over the past few years, virtual private network usage has surged as more people look to improve their online security and privacy. Using the best VPN will encrypt your personal data, secure every Wi-Fi network you use, and protect against DDoS attacks – but more and more people are asking the question: How does a VPN work?

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Along with offering a range of security and privacy benefits, VPN services also allow users to unblock geo-restricted online content, stop bandwidth and data throttling, find the cheapest deals on the internet, and so much more.

While VPNs offer lots of different benefits, you’re probably wondering how they operate. These services rely on a range of crucial technologies, such as encryption and protocols, and unless you’re a technical expert you might not know what these things mean. Here, we’ll be exploring exactly how VPNs work, and we’ll also suggest a few of our favorites.

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What does a VPN do?

Although there are lots of VPN services on the market, they all work in much the same way. In simple terms, a VPN is a software-based tool that provides an end-to-end encrypted tunnel between your connected devices and a VPN server. This effectively routes your traffic away from your ISP’s servers and through its own.

In this tunnel, web traffic sent to and from your computer will be encrypted at all times. What’s more, a VPN server will hide your internet protocol (IP) address. Therefore cybercriminals, government agencies, internet service providers, companies, and other third parties can’t intercept your personal data, track your online movements, or see where you’re located in the world.

However, something to bear in mind is that VPNs aren’t just helpful security and privacy tools. VPN services typically provide servers worldwide, and by connecting to a global network of servers, you can spoof your location to bypass geo-restrictions and unblock online content that would normally only be available in a specific country. This makes VPNs perfect for streaming. 

So, in short, a VPN redirects and encrypts your internet traffic, making it effectively invisible to anyone on the outside – including your ISP.

What is VPN encryption?

One of the most important functions of VPNs is their ability to encrypt personal data and web traffic. Using encryption technologies, VPNs ensure that credit card numbers, passwords, messages, transaction history, browsing data, and other sensitive information travels through an encrypted tunnel in undecipherable code.

How does this work in practical terms? Well, if you tried logging into your email account, this request would be communicated to the VPN service. After establishing a connection between your device and a VPN server, the VPN service would send your login request to the VPN server via an encrypted tunnel.

Once the VPN server has received this request, it’d send the data to your email provider’s server, still encrypted. The email server would then get the request, grant it, and return this data to your VPN server. At this point, the VPN server would re-encrypt and dispatch it to your VPN service. Lastly, the VPN service deciphers this data before sending it to your device. 

At every step of this process, your data is encrypted and decrypted. While the VPN encryption process may seem long and complicated, Surfshark points out that every step “happens in a second” – and sometimes “in a fraction of a second” if you have a fast internet connection. The vast majority of VPN services use one of the most robust encryption methods available, AES-256.

How does a VPN work?

What are VPN protocols?

In addition to encryption, another fundamental part of VPNs is their protocols. So, what are they? VPN protocols are essentially commands and processes that decide how web traffic travels from one server to another within an encrypted tunnel. 

NordVPN says every protocol provides a “different solution to the problem of secure, private, and somewhat anonymous internet communication”. There are lots of VPN protocols out there, but the most common are Secure Sockets Layer (SSL), Transport Layer Security (TLS), Point-to-Point Tunneling Protocol (PPTP), IP Security (IPSec), Internet Key Exchange (IKEv1 or IKEv2), Layer 2 Tunneling Protocol (L2TP), WireGuard, and OpenVPN.

But with VPN services constantly evolving, protocols quickly become outdated and new ones enter the industry. NordVPN believes every protocol is imperfect, explaining that “each may have potential vulnerabilities, documented or yet to be discovered, that may or may not compromise your security”. 

At their core, most VPN providers currently use the OpenVPN and WireGuard protocols, which are highly secure and generally very fast. However, what you'll find is that many VPN services allow users to switch between different protocols. So, if there’s one you prefer, you can use that as your main VPN protocol. Usually, you’ll need to go into the settings of your VPN app to change protocols. 

Being aware of these different protocols is important because they often determine the overall speed, security, and privacy of your VPN service. Using an outdated VPN protocol could potentially put your online data and experience at risk. In short, OpenVPN, WireGuard, and proprietary protocols like ExpressVPN’s LightWay and Hotspot Shield’s Catapult Hydra are widely regarded as safe, with IKEv2 also being useful for mobile VPN applications. Others have their uses, but in modern VPNs, we’d highly prioritize the use of these protocols for both speed and security.

How VPNs can unblock streaming sites

As we’ve already mentioned, VPNs are capable of much more than simply keeping users safe on the internet. With many of the top streaming VPN services, you can unblock streaming platforms globally.

But how? It’s actually pretty simple. Most premium VPN providers operate thousands of servers globally, and when you connect to these, you can appear to be elsewhere in the world and subsequently avoid geo restrictions. For example, if you want to access the US Netflix catalog in the UK, you’ll need to find a US VPN server and connect to it. Then, Netflix will see you're connecting from a US IP address and think you’re physically located in the US, and provide access to its American streaming catalog. 

In a nutshell – How does a VPN work?

In short, a VPN redirects your traffic away from your ISP's servers and send it through its own. While doing that, it encrypts it so no one else can read it, even it were to be intercepted.

VPNs use a number of different protocols to transfer your data, with OpenVPN and WireGuard now considered the most popular and secure. 

While VPNs function well to protect your data, many use them to unblock streaming content from overseas. That's possible thanks to global networks of servers owned by a particular service, and by routing through a server in a different area, you can trick sites into thinking that you're really there.

Overall, VPNs are extremely handy applications and provide lots of different functions. Now that you know more about how they work, you should be in a better position to choose a VPN provider that suits all your needs. However, if you’d like to learn more about VPNs, check out our What is a VPN? guide. 

Which VPNs do we recommend?

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ExpressVPN – our top-rated service today
With over 3,000 servers worldwide and excellent speeds on just about all of them, ExpressVPN is a versatile, secure solution. You can test it out risk-free for 30 days and claim your money back, and now Tom's Guide readers can get three months absolutely FREE. What more could you ask for?

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NordVPN – big name offers serious security
Arguably the biggest name in the VPN industry, it's quite likely you'll have heard of NordVPN. Thankfully it's not all hot air, as Nord delivers a premium service that's hugely secure and great for streaming – and at just $3.71 a month, it's decent value, too.

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Surfshark – best-value VPN on the market
If you're after a premium service for as little money as possible, Surfshark will be right up your street. With top streaming performance and intuitive apps on just about every device, it's the perfect bargain option at just $2.49 a month.

Nicholas Fearn is a freelance technology journalist and copywriter from the Welsh valleys. His work has appeared in publications such as the FT, the Independent, the Daily Telegraph, The Next Web, T3, Android Central, Computer Weekly, and many others. He also happens to be a diehard Mariah Carey fan!