A Virtual Private Network, or “VPN”, is a private Wide Area Network that allows the client to connect to public networks while protecting their own personal information. If you have ever had to remotely connect to a server for work, there is a very good chance you did so using a VPN. Corporations have been using proxy servers and VPNs for a long time to protect their internal data, but now the technology is available to everybody. From the moment you connect to your VPN, all of your information is immediately private and encrypted, and you can even spoof your location!


But how does a VPN actually work? Read on in our guide to find out!




The heart and soul of a VPN is encryption, a form of digital cryptography that protects information during transmission from one place to another. Humans have been using cryptography to send encoded messages for at least as long as we have had written language, but these days computers use sophisticated algorithms to generate encrypted code that can only be decrypted by set of very specific keys.


A basic version of this is symmetric key encryption. This requires the same key to be owned on each computer that will be sending and receiving encrypted communication, and the security of a key is judged by the number of bits it uses to build a wall around your information. For example, a 128-bit key (which is considered minimum security), has over 3.0 x 1035 possible combinations that a computer would have to guess through before it was able to crack the communication.


How does a VPN work?


Symmetric-key encryption is fast, but it is still possible for an unauthorized listener to pick up the key during transmission from point A to B if they know the key that’s stored on one of the local machines. Asymmetric or public-key encryption uses both a public and a private key to encrypt data. In public-key setups, only the sending device knows the private key, while sharing the public key with its intended recipients. The recipient needs both the public key and another private key to decrypt the information. Device A uses one private key to encrypt its data, and then encrypts that key with the public key. Device B uses its own private key to decrypt the public key, and then uses the public key to decrypt the information. Websites acquire digital certificates (SSLs) from certificate authorities who share the appropriate public keys between authorized senders and recipients.

VPNs use a combination of public-key encryption and authentication to ensure all the information passing through their channels is consistently protected at the highest levels. VPNs use a number of protocols in tandem with one another for the best possible results, but how do they actually work?



Security Protocols


VPNs follow specific security protocols to ensure they are operating at the highest standard for encryption and personal privacy at all times. The first protocol VPNs use is called the Point-to-Point Tunnelling Protocol (PPTP), which has been around for a long time and provides an encrypted channel, or “tunnel”, through which information can pass securely. PPTP itself is simply a transport method and does not encrypt the data itself, so it’s often employed alongside with other protocols.


Communications, for instance, might be secured by IP Security (IPSec). IPSec can encrypt just the message (in Transport mode) or the entire packet of data (in Tunnelling mode). Digital certificates are secured using Secure Sockets Layer (SSL) or sometimes Transport-Layer Protocol (TLP). You can easily identify websites with these digital certificates because the URL will begin with https://, where the s stands for – you guessed it – “security”.


How a VPN works


Like PPTP, a Secure Shell (SSH) transports unencrypted data through an encrypted channel. Although all of the information travels through specific ports on a remote server to ensure security, the data itself remains unchanged. In contrast, Layer 2 Tunnelling Protocol (L2TP) works with IPSec to create a VPN with both encrypted channels and data. IPSec works to encrypt the data while L2TP creates the secure encrypted tunnels through which all information travels.




A strong VPN combines public-key encryption according to a reputable security protocol, with a well-established transport protocol to give you the best guarantee of total security you’re going to find online. 


Researchers and developers are working fulltime to develop new protocols and try different combinations of each in order to continually raise the benchmark for security across the board. The number of applications that communicate with the web is increasing every day, and now you can use a VPN for almost anything, whether it’s connecting to a public wireless network, securely browsing the web without fear of government surveillance, protecting against identity theft while shopping online, streaming content from Netflix or Hulu, and even securely connecting to public networks on mobile devices such as iPhones and Androids. ProVPN provides a layer of protection that keeps your identity safe from hackers online!


To see the full range of what you can do with a good VPN, check out our How-To articles that cover these topics and so much more.