The Windows Club

What is Website Traffic Fingerprinting? Is it dangerous?

We had earlier written on Browser Fingerprinting where it was possible for websites to know who is the person visiting them. Website Traffic Fingerprinting or traffic fingerprinting is a similar method. It allows third parties to snoop on you and get an idea of what you do on the Internet. The article explains how it is possible and then talks if it is dangerous.

Website Traffic Fingerprinting

Website Traffic fingerprinting is a method to determine when and what a user does on the Internet. The user in question may be using a proxy or a secure tunnel VPN, encryption, etc. But still, it is possible to determine the person’s usage of Internet via snooping on the data packets traveling to and fro on the Internet.

Even TOR Network (The Onion Router) says it is possible for criminals to decode things being done by its users. In its blog, TOR said that data is encrypted and sent forward. We all know there are many nodes in the TOR network so that authorities cannot track the users. But then, website fingerprinting comes in. For TOR also, the data packets are vulnerable until they reach the first node in the TOR network. This information can easily be obtained. If the authorities or criminals set up multiple nodes on the TOR network, there are high chances of data passing through them. When such things happen, they snoopers rip off the encryption to know where the data packets are going.

But Website Traffic Fingerprinting is not only about the TOR browser. It is about how people snoop on you to know what you are doing on the Internet and how they make use of that information.

What motivates Website Traffic Fingerprinting

According to the TorProject,

“The exact motivation for this effort on behalf of the adversary is typically not specified, but there seem to be three possibilities, in order of increasing difficulty for the adversary:

  1. The adversary is interested in blocking specific censored webpage traffic patterns, while still leaving the rest of the Tor-like traffic unmolested (perhaps because Tor’s packet obfuscation layer looks like something legitimate that the adversary wants to avoid blocking). NOTE: You may replace TOR with any other encrypted traffic.

  2. The adversary is interested in identifying all of the users that visit a small, specific set of targeted pages.

  3. The adversary is interested in recognizing every single web page a user visits.”

How does Website Traffic Fingerprinting work?

Website traffic fingerprinting, or simply ‘traffic fingerprinting’, works on the client end. That is, snoopers study the data packets entering and leaving a website. As said earlier, it could just be a marketing guy who is interested in knowing what types of websites get more views – or it can be some authority tracking your moves even if you try a proxy, VPN or other forms of secure browsing.

The way data leaves and enters a website says a lot about what is being viewed, buffered or being downloaded. If the data packets are huge and the time interval among releases is too high, it indicates that the user is on some video site.

Likewise, if the data packets are pretty small and leave the website at a very low interval, it could be an email website, or someone just reading a website.

Based on these patterns, one can understand what is going on. But unless they break the encryption, they can’t know about the specific data being transferred.

Dangers of Website Traffic Fingerprinting

The only deadly danger is that website traffic fingerprinting might blow off your identity. It won’t steal your data in any way if you are using VPN or other forms of encryption. The main purpose is to know the user and what are his/her interests on the Internet. The method is mainly used for encrypted packets to check if something illegal is being done. I do not think it can be used for anything else. There is no need to panic if you are using encrypted connections.

This above is my take on Website Traffic Fingerprinting. If you feel like adding something, please do.