What Is Traffic Obfuscation?
Traffic obfuscation is a technology that makes outgoing internet traffic difficult to distinguish from regular web traffic. Originally, it was widely used to hide Tor traffic, but over time, VPN services have also adopted it.
Why Is Traffic Obfuscation Needed?
Traffic obfuscation can, for example, hide the fact that you are using a VPN or Tor. The data packet patterns transmitted by these tools are noticeably different from those of normal web browsing. Obfuscation makes VPN or Tor traffic appear to monitoring equipment as if it’s just regular user activity—like visiting ordinary websites.
Why Is the Traffic Obfuscation Feature Important?
This feature is essential for users who need access to content during internet blockages, such as in China, Iran, and other countries where much of the internet is censored or blocked. Its importance lies in helping people bypass restrictions and gain freedom of access to information.
The Most Popular Traffic Obfuscation Tools
There are many ways to obfuscate traffic, but here are the most popular and well-known tools:
- obfs4 – This transport protocol was developed primarily for Tor and makes transmitted traffic appear “random” or “normal,” complicating analysis or blocking by altering the data packets. It’s the most popular tool used by VPN services that offer traffic obfuscation. Services like TunnelBear and CactusVPN have been known to use it.
- meek – While relatively rare, meek is significant in the field of censorship circumvention. It uses Domain Fronting technology, which is also found in other tools like V2Ray. Domain fronting hides the true destination of a connection by leveraging features of content delivery networks (CDNs). This makes the traffic look like it’s going to major sites like Google or Amazon. Its use in VPN services is debated, but some experts claim ExpressVPN uses Domain Fronting in its Lightway protocol.
- Shadowsocks – Created some time ago to bypass the Great Firewall of China, Shadowsocks can use encryption depending on settings and other factors. Technically, it’s based on the SOCKS5 proxy protocol but is significantly different in terms of encryption and obfuscation features. However, it also allows for unencrypted servers, which can leave inexperienced users’ traffic unprotected and easily analyzed. If you’re not a tech-savvy user who can configure it properly, it’s better to consider other technologies.
Why Don’t “VPN” Browser Extensions Have Traffic Obfuscation?
- Modern browsers don’t allow manipulation of traffic at a low level. “VPN” extensions simply tell the browser which proxy server to use for which site.
- When using an HTTPS proxy, the traffic already looks like HTTPS to monitoring equipment, so there’s no need to disguise it further.
The only caveat is that, until new encryption standards are widely adopted (like the ECH standard, available only in Chrome version 107 and above), it’s possible to see which server name the browser is connecting to when using a proxy. This can reveal that a proxy is being used. However, most filtering equipment currently doesn’t analyze traffic to determine if the destination server is a proxy, and there’s hope that browsers and servers will soon support the new standard, making it impossible to extract this information from encrypted packets.
Does Traffic Obfuscation Really Help?
Absolutely—traffic obfuscation helps many users in various countries. Experts continue to research blocking methods and ways to bypass them, which not only benefits users technically but also advances research and knowledge in the field.