WTF are VPN Protocols?

An ordinary VPN user, on most occasions, won’t encounter VPN protocols first hand and won’t have to make any changes regarding them. Be it L2TP/IPSec, IKEv2, OpenVPN or any other acronym — for most, it means very little.

But protocols are one of the most important parts of any VPN. Another reason is they are technical and hard to understand without basic networking knowledge.

Due to the tragic outburst of COVID-19, many employees faced the challenge of working from home, and the use of VPNs for safe and remote access skyrocketed.

That’s why I believe it’s essential to start working on the basics of their functionalities because using cybersecurity software always demands some knowledge, and knowing at least superficially about different aspects of it may help choose the right one for the occasion.

To understand protocols, it’s helpful to understand what is the Internet and a concise history of its development. At the very beginning, in 1969 a militaristic computer network called ARPANET came into being. Comparing to the Internet of nowadays it was a small network of interconnected computers.

As the ARPANET expanded, it was becoming difficult to manage, and the network was split in two: MILNET that was dedicated for military use, and ARPANET was left for nonmilitary purposes.

To link MILNET with ARPANET, the Internet Protocol was developed, which is widely used to this day. Its purpose is to allow communication between separate interconnected computer networks and establish the laws on how it’s done.

Thus it’s easy to understand what Internet Protocol is: it’s a set of rules that govern the interaction between two or more networks and allow efficient exchange of data between them. Information in computer networks are called packets, and the Internet Protocol is paired with Transmission Control Protocol that governs how information is divided into packets and sent further down the network.

To summarize, in computer science, a protocol is a set of rules that govern how data is defined and exchanged in computer networks, and it works on different levels. On a very low level, a protocol defines what do different electromagnetic impulses mean, in layman’s terms, what is a 0 and a 1 in a binary system. On a high level, it defines how applications communicate with other applications and computer hardware.

VPNs work by establishing a secured tunnel between a device and a VPN server and encrypt all data that flow within that tunnel. But there’s more than one day to do this, and that’s what a VPN protocol defines.

A VPN protocol is a set of rules that govern the way a secured tunnel is established and the way encryption is applied for the data-flow. In other words, it’s a solution to the problem of private and safe communication between separate devices within a computer network.

Naturally, there can be more than one solution, and VPN protocols can differ in the level of speed, security, and reliability.

As examples, I took the three most widely used VPN protocols, and one that will most likely be widely implemented, so let’s go over each.

OpenVPN is considered to be the most popular and widely used VPN protocol out there. It’s also open-sourced, which means that any issues or vulnerabilities can be spotted by the supporting communities and fixed in a timely manner.

OpenVPN supports a wide array of encryption algorithms and is balanced between speed and security. It can also evade port-level VPN blocking by “pretending” to be a regular HTTPS traffic. It’s the number 1 go-to VPN protocol in most cases and is highly recommended.

IKE (Internet Key Exchange) is a tunnelling protocol that is paired with Internet Protocol Security (IPSec). It has been developed by two IT giants — Microsoft and Cisco, which is a bit of a down-turn because it’s a closed environment that has corporate interests. Which usually doesn’t build trust when it comes to VPNs.

However, IKEv2 supports ‘multihoming’ technology, which means that they can maintain the VPN tunnel when Wi-Fi data is switched to mobile data, making it one of the more popular VPNs for mobile devices. Another thing is that IKEv2 is very fast in comparison to other VPN protocols, so when privacy is not of the utmost importance and when considering a VPN for mobile, this is highly advisable.

Layer 2 tunnelling protocol is also paired with Internet Protocol Security. It’s one of the older VPN tunnelling protocols, alongside Point-To-Point-Tunneling protocol PPTP. The latter is rarely used these days because of weak encryption support and many known vulnerabilities. While L2TP/IPSec does not suffer from the same vulnerabilities, it is easily detectable, and if you’re browsing in a country where VPN use is restricted, then it shouldn’t be your first option. On the other hand, for casual use, this protocol offers decent speeds and sufficient security features to be widely used.

Wireguard is a new, but up-and-coming, kid in town. Released as open-source in 2016 it aims to be faster, more secure and more comfortable to implement protocol than OpenVPN and IPSec.

One of the key differences is its compact size, consisting of only 4000 lines of code in comparison to 400k lines of code of OpenVPN. This makes it easier to deploy and easier to audit for bugs and vulnerabilities than it’s predecessors.

So far, it received positive feedback; however, it’s implementations are going slower because it still has security vulnerabilities. On the other hand, commercial VPN service providers, such as Mullvad and NordVPN, have already started working on security upgrades that would allow safe usage of this promising VPN protocol.

Also, very recently another prominent VPN service provider PIA announced the closed beta of their service running on this protocol. If privacy and security are not necessary, then you can surely give these services a try!