Tarayıcı parmak izi. Bölüm I

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Browser fingerprint. Part I​

What are browser fingerprints?​

This is the method used by sites and services to track visitors. Users are assigned a unique identifier (fingerprint). It contains a lot of information about the settings and capabilities of the user's browser, which is used to identify them. In addition, browser fingerprint allows sites to track behavioral patterns in order to further identify users more accurately.

The uniqueness is about the same as that of real fingerprints. Only the latter are collected by the police to search for suspected crimes. Browser fingerprint technology is not being used to track criminals at all. We're not criminals here, are we?

What data does browser fingerprint collect?​

We knew that a person can be tracked by IP since the dawn of the Internet. But in this case, everything is much more complicated. The browser fingerprint includes the IP address, but this is far from the most important information. In fact, you don't need an IP to identify you.

According to research EFF (Electronic Frontier Foundation) The browser fingerprint includes:

• User-agent (including not only the browser, but also the OS version, device type, language settings, toolbars, etc.).
• Timezone.
• Screen resolution and color depth.
• Supercookies.
• Cookie settings.
• System fonts.
• Browser plugins and their versions.
• Visit log.

According to the EFF study, the uniqueness of the browser fingerprint is very high. If we talk about statistics, then only once in 286,777 cases there is a complete coincidence of the browser fingerprints of two different users.

According to another one study , the accuracy of user identification using the browser fingerprint is 99.24%. Changing one of the browser settings reduces the accuracy of user identification by only 0.3%. There are browser fingerprint tests that show how much information is collected.

How browser fingerprint works​

Why is it even possible to collect information about the browser? It's simple - your browser communicates with the web server when you request a website address. In a normal situation, sites and services assign a unique identifier to the user.

For example, "Gh5d443ghjflr123ff556ggf" ...

This string of random letters and numbers helps the server know you, associate your browser and your preferences with you. Actions that you take online will be assigned approximately the same code.

So, if you went to Twitter, where there is some information about you, all this data will be automatically associated with the same identifier.

Of course, this code will not be with you for the rest of your days. If you start surfing from a different device or browser, the identifier will most likely change too.

How do sites collect user data?​

It is a two tier process that works on both the server and client side.

Server side

Site access logs

In this case, we are talking about the collection of data sent by the browser. At least this:

• The requested protocol.
• The requested URL.
• Your IP.
• Referer.
• User-agent.

Headings​

The web servers receive them from your browser. Headers are important because they make sure the requested site works with your browser.

For example, header information lets the site know if you are using a PC or mobile device. In the second case, there will be a redirect to the version optimized for mobile devices. Unfortunately, the same data will end up in your fingerprint.

Cookies​

Everything is clear here. Web servers always exchange cookies with browsers. If you specify the ability to work with cookies in the settings, they are stored on your device and sent to the server whenever you visit a site that you have already visited before.

Cookies help you surf more comfortably, but they also reveal more information about you.

Canvas Fingerprinting​

This method uses the HTML5 canvas element, which WebGL also uses to render 2D and 3D graphics in the browser.

This method usually "forces" the browser to process graphical content, including images, text, or both. This process is invisible to you, since everything happens in the background.

Once the process is complete, canvas fingerprinting turns the graphics into a hash, which becomes the unique identifier we talked about above.

This method allows you to get the following information about your device:

• Graphics adapter.
• Graphics adapter driver.
• Processor (unless there is a dedicated graphics chip).
• Installed fonts.

Client side logging​

This assumes that your browser is exchanging a lot of information thanks to:

Adobe Flash and JavaScript​

According to the FAQ AmIUnique , if you have JavaScript enabled, then data about your plugins or hardware specifications are transmitted outside.

If Flash is installed and activated, this provides the outside observer with even more information, including:

• Your time zone.
• OS version.
• Screen resolution.
• Complete list of fonts installed on the system.

Cookies​

They play a very important role in logging. So, you usually need to decide whether to allow the browser to process cookies or delete them completely.

In the first case, the web server receives just a huge amount of information about your device and preferences. If you do not approve of using cookies, sites will still receive some data about your browser.

Why is browser fingerprint technology needed?​

Basically, in order for the user of the device to receive a website optimized for his device, regardless of whether he went to the Internet from a tablet or smartphone.

In addition, the technology is used for advertising. It's just the perfect data mining tool.

So, having received the information collected by the server, suppliers of goods or services can create very finely targeted advertising campaigns with personalization. Targeting accuracy is much higher than using just IP addresses.

For example, advertisers can use browser fingerprints to get a list of site users whose screen resolutions can be called low (for example, 1300 * 768) who are looking for better monitors in the seller's online store. Or users who just surf the site without intending to buy anything.

This information can then be used to target ads for high-quality, high-resolution monitors to users with small and obsolete displays.

In addition, browser fingerprint technology is also used to:

• Detection of fraud and botnets. This is a really useful function for banks and financial institutions. They allow you to separate user behavior from the activity of attackers.
• Definition of VPN and proxy users. Intelligence agencies can use this method to track Internet users with hidden IP addresses.

Ultimately, even if browser fingerprints are used for legitimate purposes, it still has a very negative impact on user privacy.

Plus, browser fingerprints can be a hacker's best friend. If they know the exact details of your device, they can use special exploits to compromise your device. There is nothing difficult about this - any cybercriminal can create a fake site with a fingerprint script.

Recall that this article is only the first part, there are two more ahead. They address the issues of the legality of the collection of personal data of users, the possibility of using this data and methods of protection against too active "collectors".

A source

 

[Матушкин Андрей Николаевич]

Что такое отпечатки браузера?​

Это метод, используемый сайтами и сервисами для отслеживания посетителей. Пользователям присваивается уникальный идентификатор (отпечаток). Он содержит много информации о настройках и возможностях браузера пользователей, что используется для их идентификации. Кроме того, отпечаток браузера позволяет сайтам отслеживать поведенческие паттерны, чтобы впоследствии еще точнее идентифицировать пользователей.

СПАСИБО!

 

[Частный детектив. Армения. Ереван.]

Thanks for the interesting article)

 

[Частный детектив Донецк]

Now I understand everything) Thank you!

 

[Kiril Harchevnikov]

Thank you for the article!

 

[David Mamedov]

Thanks for the post!

 

[Частный детектив. Москва.]

I'm waiting for parts 3 and 4!

 

[частный детектив. Узбекистан. Ташкент.]

It was interesting to read

 

[Детективное агентство Израиль.]

It turned out very interesting!

 

[seventeam]

As always, it was interesting to read