An Ultimate Guide to Canvas Fingerprinting

Did you realize that when you visit a website these days, the website owners may track you in various ways? According to Ghostery, a famous free software supplier, 79% of websites with unique domains gather user data. We’ve already discussed one such approach, known as browser fingerprinting. In this post, you’ll learn about the canvas

Did you realize that when you visit a website these days, the website owners may track you in various ways? According to Ghostery, a famous free software supplier, 79% of websites with unique domains gather user data.

We’ve already discussed one such approach, known as browser fingerprinting. In this post, you’ll learn about the canvas fingerprint, which is one of the most inventive and effective ways to trace you.

However, if you are concerned about your privacy, you may find this concept irritating.

So we’re here to educate you on what canvas fingerprinting is, how it works, why websites use it, the benefits and drawbacks, and how to prevent it.

So, tune in, folks!

What is Canvas Fingerprinting?

It’s no secret that the website owners tracked you with IP addresses and HTTP cookies. Such conventional methods are replaced with web beacons, browser fingerprinting, and canvas fingerprinting.

Before diving into canvas fingerprinting, it’s essential to understand a browser fingerprint. The significant difference between the Canvas and other fingerprinting methods is that the former leverages the HTML5 Canvas feature to track the visitors’ digital footprint.

In browser fingerprint, the browser collects the following :

• User-agent (UA) string
• Operating system (OS)
• Device model
• Time Zones
• Timestamp
• File format identifiers
• Language settings
• Plugins
• Extensions
• Screen resolution

A browser generates a unique fingerprint when it puts all the above entities into a single cluster. There are no two 100% identical fingerprints.

Canvas fingerprinting is a form of browser fingerprinting technique that uses the HTML5 canvas element to create an image or text in the backdrop (more on this in the following section).Ideally canvas fingerprinting is superior to other approaches such as cookies since it occurs without the users’ awareness. Still, whether it is illegal or not, we shall discuss later.

The specific manner in which the browser generates this text/image, on the other hand, reveals detailed information about your Operating System, installed fonts, browser, IP address, graphics card, and graphics card driver.

As with browser fingerprinting, no two canvas images are the same, even if they look identical. This can be attributed to two factors:

1. Image level: The image-processing engine, browser compression levels, and export options may change between browsers.
2. System level: The system level concerns aspects of the operating system such as the OS version, fonts installed by users, and settings for sub-pixel display and anti-aliasing.

How does Canvas Fingerprinting work?

Canvas fingerprint occurs when the website you visit gives the browser the task of drawing a canvas object. This canvas object is simply a tool that most websites use to create simple and complex graphics.

To begin with, websites use JavaScript to instruct the browser to generate an image using a canvas object and a predetermined script. The image may have sophisticated patterns such as various lines, colors, geometrical shapes, various backgrounds, or you may find the image distorted in different ways.

As discussed previously, even if the two canvas images look identical to the naked eye, they are never the same. 

Now let’s look at a concept called hash functions which may help you better understand how the canvas operates.

How does hash incorporate into canvas fingerprint

The hashing notion takes a piece of data, such as text, music, or images, and compresses it into a predefined data element while preserving its individuality.

Although there are various types of hash functions, they all do the same task of reducing the amount of data for fast and easy comparison. Typically users use the hashing functions for quick and more accessible comparisons, although there are numerous other uses.

So for canvas fingerprinting, the hashtag is vital because it produces the same output as long as the input remains the same. For instance, if you use the online hash function SHA256 for a particular text such as Canvashtml5, it will produce the below output:

9fc74421318cd92a2f3970c9a4f102cf7fed1c40f9559d9d899245e1c4e4e1b1

However, if you change the input, let’s say, canvas html5, it would produce a different output:

C98a47aa75596059ef231952d421dd03961041fce2396cd0afe7c7ba280a9323

So as you can see, no two different inputs produce the same result.

Another use of the hash function is that hashing functions are non-reversible. This means you would be able to turn any piece of input data into a hash, but you’ll not be able to reverse it back to the original input.

Furthermore, applying a hash function to multiple pieces of information makes it hard to discern how similar or unlike the original inputs were. Unfortunately, this feature does not affect the effectiveness of canvas fingerprinting.

Drawing Images with Mathematical Formulas

When software developers design an image inside the canvas, it is not the same as painting graphics in MS Paint or other conventional graphical tools. First, you’ll need two coordinates (x and y) to determine the circle’s center, followed by the radius stated in pixels.

So, after you have the coordinates and the radius, the computer draws the circle by filling all the pixels within R distance with the radius. That’s all there is to it, and you might think it’s as simple as a piece of cake.

The actual test for developers comes when they begin designing complicated pictures. They would have to rely on JavaScript to render varied shapes, shadows, colors, and sophisticated backdrops in such cases.

Benefits of Canvas Fingerprinting

As mentioned earlier, canvas fingerprints happen without users’ knowledge, unlike cookies. You can delete a cookie file in your browser, but you don’t know where the canvas image lives. With that being the case, canvas fingerprint does have benefits to internet users and web services. In this section, we’ll talk about a number of them.

Content Personalization

Brands use online tracking tools such as cookies and browser fingerprinting to provide customers with a customized experience. As previously said, cookies are gradually becoming outdated, while other tracking technologies such as canvas fingerprinting are gaining center stage.

Personalization of content results in a better user experience for internet users and more profitability for brands. Therefore marketers understand the concept of personalization very thoroughly. According to studies, 91 percent of consumers prefer to buy with businesses that provide a personalized experience through innovative products and referrals.

To prevent Ad-fraud

Over the last decade, the expansion of internet banking has increased online fraud and theft. Online banking commonly employs online tracking to verify that only you, as a client, have access to your bank account. Add to that a canvas fingerprint, which safeguards your online banking even further.

Canvas fingerprints, for example, can identify whether there is a vulnerability in an online banking session. In general, there are footprints in devices you use to access a credit or debit card payment page. As a result, any log-in through a new footprint would show that fraud had happened.

For Analytics and Tracking

One of the crucial aspects of today’s digital business is analytics and tracking. Without the analytics, it would be challenging for marketers and other stakeholders in your business to make effective decisions to optimize future campaigns and determine the ROI(Return Of Investment). This is where canvas fingerprint plays a crucial part by enabling you to collect helpful statistics such as demographic information.

Target ads

Online advertisements are one area that marketers invest into target campaigns for different market segments. However, marketers need to implement this tactic effectively to ensure that they do not invest in potential customers who are not interested in purchasing their products.

Canvas fingerprint is a technique they could rely on to segment products for target markets effectively. In the past, marketers, and advertisers relied on cookies. However, the downside of using cookies is that users could delete them. This is where canvas fingerprint has the edge.

Downsides of Canvas Fingerprinting

Like a coin has two sides, most entities in real life have good and evil. That applies to canvas fingerprinting as well. Here are its two significant downsides:

You become the target of advertising companies

Some websites create your browser fingerprint and merge it with your browsing history to construct your profile. It then makes this profile available to o third-party advertising partners. Then such partners will bombard you with adverts wherever you go on the Internet. Then you may get bored or frustrated as a result.

Ugly Invasion of privacy

You are already aware by now that marketing firms track your canvas fingerprint to boost their ad campaigns. However, they may fall into the wrong hands, such as Government agents (if you reside in a country with strict censorship on online content), Spy, and other security agencies.

These agents can then view your online activities. This indeed results in an ugly invasion of your privacy, although you’re not carrying out any illegal activities. Then it may appear to you suddenly that you must shield yourself from canvas fingerprinting.

How to combat canvas fingerprinting?

It’s quite an overwhelming task to block or avoid canvas fingerprinting. This is because it works with the culmination of several mechanisms such as browser fingerprinting, IP tracking, and cookie tracking.

Turning JavaScript off

The only guaranteed way to stop yourself from canvas fingerprinting is by disabling JavaScript. But would you want to compromise user experience by disabling JavaScript? Besides, the websites that frequently track you using canvas will block you with disabled JavaScript.

So as you can see, blocking Javascript is not the ideal option. So let’s look at what other options you have.

Tor browser

Tor browser is one of the most popular methods to prevent canvas fingerprinting. This privacy-protection browser is at the top of browsers and leverages the TOR network to hide your IP address.

It solves the canvas fingerprinting mechanism by notifying users of canvas reading attempts and offering the option to provide blank image data. This implies providing false information.

Other Tools and browser extensions

AdBlock Plus stated that their software could prevent canvas fingerprinting and has been working for years. It works by preventing scripts from setting cookies, hence preventing canvas fingerprinting. Other browser-based extensions selectively block Javascript, such as Mozilla Firefox’s NoScript and Google Chrome’s ScriptSafe.You might also try Blur and Privacy Badger.

Frequently Asked Questions about Canvas Fingerprinting

Could you Completely avoid Canvas Fingerprinting?

Due to the sheer way the web and web technologies are built today, eliminating tracking is tricky unless you are ready to go the additional mile and forego the user experience given by JavaScript. Instead of preventing canvas fingerprinting, you should enable it but often utilize the extensions mentioned above or the Tor browser to remove fingerprints. They will lose if they have too many of your fingerprints.

So, in summary, preventing canvas fingerprinting is like you wearing a face mask in front of a crowd who doesn’t wear it. Then you’re likely to be more suspicious. So it can only be effective if all the users can avoid it, which is negligible.

Conclusion

I’m sure you have come across what canvas fingerprinting is and how it evolves in this article. While blocking it altogether would be near impossible, we recommend that you control it so that you’ll not be easily identifiable as opposed to with it. Finally, you would be able to use some of the techniques we have mentioned above to minimize it in contrast to blocking it completely.