Using a VPN is always a good idea. It hides your identity, encrypts your traffic, bypasses internet censorship, and grants you access to restricted content. Sadly, governments and online services learned to detect and block VPN traffic.

As websites and network admins tried implementing new and improved anti-VPN measures, VPN providers started providing features to counter these blocks. One such feature is VPN obfuscation, also called traffic obfuscation, VPN cloaking, or stealth VPN. But what do these terms really mean?

What Is VPN Obfuscation?

how do vpns work

VPN obfuscation refers to the set of features that disguise VPN traffic as normal internet traffic. This allows users to circumvent VPN blocks and use a VPN even in a highly restrictive region like China.

To understand the process better, consider how information travels through the internet. All the data is broken into small chunks called packets, as it travels from the source to the destination. These data packets contain the raw information as well as the metadata about the type of protocol used to deliver the data.

As you encrypt your traffic with a VPN, websites and online services can see traces of the VPN and deny you access to the platforms. They do so by looking at the encryption patterns and detecting unique VPN signatures.

With VPN obfuscation, all the VPN metadata is removed from the data packet, so VPN blockers and firewalls can’t tell that you’re using a VPN and let the packets pass through as regular traffic.

VPN providers achieve obfuscation by using specialized obfuscated servers, proxies, and stealth protocols that conceal the use of VPNs. So how do they work, and what benefits do they offer over regular VPN servers?

How Does Obfuscation Work?

Depiction of an anonymous VPN connection

To understand obfuscation, it's important to learn how a VPN works. When you use a VPN, your data gets encrypted as it passes through a VPN tunnel. It also gets a unique encryption pattern and a distinctive VPN signature during the process. The data in itself is secure but firewalls and anti-VPN software can see a VPN in use, and thus deny access to websites and services.

VPN obfuscation removes all the VPN-related data from the data packets, so no one can tell that it’s coming from a VPN. The purpose of an obfuscated server or a stealth VPN is to conceal the nature of its traffic and make it appear as normal internet traffic.

There are several ways VPN providers use to achieve obfuscation.

1. Obfsproxy

Image depicting servers in a cloud background.

Obfsproxy, or obfuscated proxy, is a Tor subproject that was designed to get around blocks on the Tor browser. It works by changing the nature of your internet traffic to regular HTTP traffic and wrapping it in a protective layer. Although obfsproxy was initially developed for the Tor browser, some VPNs have adopted it for use with OpenVPN.

Besides, Obfsproxy uses an unusual handshake (the first data packet when establishing a connection) that contains no recognizable byte pattern. While this protects your communication, the unnatural randomness can help ISPs and websites identify and obfsproxy traffic.

2. OpenVPN Scramble

OpenVPN Scramble, also called the XOR obfuscation, is an open-source patch that disguises the OpenVPN traffic. It takes advantage of the XOR additive cipher that replaces the value of every bit in a data packet, thus making it meaningless for Deep Packet Inspection (DPI).

Although the OpenVPN Scramble method can achieve obfuscation, it isn’t foolproof. The XOR cipher is pretty simple and can be easily cracked by advanced VPN-blocking algorithms. It can be good for users living in a country with no internet restrictions, but not particularly effective against more sophisticated firewalls.

3. OpenVPN Over SSL

A lock projected over world map

The OpenVPN over SSL takes the OpenVPN traffic and protects it in a layer of SSL encryption. This means that the VPN encryption itself gets encrypted, so even DPI can’t recognize it as VPN traffic.

This method of VPN obfuscation isn’t suitable for the average user and is rarely used by VPN services. Both the VPN provider and the user have to configure an open-source software called Stunnel on their servers and devices to hide VPN usage.

4. Shadowsocks

Shadowsocks is another open-source obfuscation technique that allows VPN providers to circumvent VPN blocks. It was developed by a Chinese programmer to bypass the Great Firewall of China, which is one of the largest censorship systems in the world.

Shadowsocks conceals VPN traffic and makes it appear like normal HTTPS traffic. VPN blockers usually don’t see any issues with HTTPS traffic and let it pass through. Unlike the other methods, Shadowsocks can be used both with OpenVPN and the relatively newer WireGuard protocol.

Why Do You Need Obfuscated Servers?

Servers with network cables plugged in

Obfuscated servers aren’t suitable for every user. They can be slower than regular servers and aren’t easy to configure. However, there are cases when only obfuscated servers would help you access restricted content. Here are some reasons you may need them.

  • Avoid VPN blocks: Some countries like China, Iran, and North Korea restrict or ban the use of VPNs. If you live in such countries or are planning to travel there, obfuscated servers could be your only chance to bypass VPN blocks.
  • Preserve your privacy: Obfuscation comes in handy in cases where you need extra privacy. It adds an extra layer of protection to your data without the ISP or network admins realizing that you’re using a VPN.
  • Avoid censorship: Some countries heavily restrict access to certain websites and services on the web. A normal VPN should be enough to evade these blocks, but sometimes ISPs and network admins go to great lengths and ban VPN traffic altogether. Obfuscated servers hide the fact that you’re using a VPN and let you access your desired content.

Get Extra Protection With Obfuscated Servers

A VPN with obfuscated servers will let you bypass VPN blocks and access content that’s blocked by your ISP, government, workplace, or school. However, not many VPN providers offer this feature. To enjoy the benefits of VPN obfuscation, make sure you pick a service that offers obfuscation as an additional feature.