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How does VPN security work?

Whether you’re thinking about using a VPN service or you already do, you’re probably wondering just how it all works. It can seem a complicated business, described in unfamiliar terms like “tunneling” and “encapsulation.” You know it protects you from hackers and spies. But how, exactly?

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VPNs are secure, private networks inside the internet

It’s there in the name: A VPN is a private network. There are many such networks, like ExpressVPN. As with any private network, the information you send and receive on a VPN is walled off from other computers and the internet.

It’s a bit like your home or business network, which you use to share files between devices across your router. Nobody outside the network can see that data if your network is properly secured. That’s why a VPN gives you security.

The key difference is in the “virtual” part of VPN. Your home or business network is secure because it’s physically separate from the internet. (You could unplug the internet connection and still share local files on it, if you wanted to.) A VPN, on the other hand, is accessed through the internet. Your data and identity, therefore, have to be secured in other ways.

How are secure VPN connections established?

How can you connect to a private network over the notoriously public internet? To use a VPN, both the network server (at the VPN provider’s side) and the client (your computer) need dedicated software. A subscription to ExpressVPN takes care of all these requirements.

To use a VPN, your computer connects to a remote access server (RAS) using valid credentials. These credentials are authenticated using any one of a number of methods called protocols. That’s the VPN’s first layer of security. Your computer also uses client software to establish and maintain your connection to the VPN. The client software sets up a tunneled connection to the RAS, as well as managing the encryption that secures your connection. Let’s have a closer look at what these are.

How VPNs use tunneling and encryption

Tunneled connections

Tunneling is a process by which data is sent privately over the internet, via a VPN. To understand tunneling, we have to remember that all data transmitted over the internet is split into small pieces called “packets.” Every packet also carries additional information, including the protocol (such as HTTP, Telnet, Bittorrent and so on) it’s being used for and the sender’s IP address.

On a VPN’s tunneled connection, every data packet is placed inside another data packet before it is sent over the internet. The process is called encapsulation.

ExpressVPN encrypts your entire internet connection.

It’s easy to imagine how useful encapsulation and tunneling are in securing your data. The outer packet provides a layer of security that keeps the contents safe from public view.

Encrypting the packets

It’s not enough just to tunnel data sent over a VPN. The next layer of security is encryption, whereby data is encoded so that packets can only be read by your VPN client and server, which are securely connected together.

VPNs can use a number of security protocols to encrypt data. The most common are IPsec (Internet Protocol security) and OpenVPN. They work by:

  1. Encrypting each encapsulated data packet’s contents with an encryption key. The key is shared only between the VPN’s server and clients.

  2. Using a sub-protocol called Encapsulation Header to hide certain packet information, including the sender’s identity, during transmission.

These two key features, along with others, keep your data and identity private online.

Why use a VPN?

Security advantages of using a VPN.

Don’t let companies use your data against you

Corporations can track the locations that you visit their websites from and adjust their prices accordingly. They can also share your data with the government. Worse, the data they collect on you is vulnerable to hackers.

Protect your personal business from hackers

Accessing Facebook or your email from a public Wi-Fi hotspot? A hacker can hijack your Facebook account or email. Stop hackers from intercepting your personal data.

Stop nosy governments from spying on you

The NSA has built the world’s largest data center in Utah. It’s bigger than Google. It’s bigger than Facebook. And it’s going to be filled with data about you and your activities. Don’t be a part of the NSA’s data center.

Learn more about using a VPN

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