Browserscan aims to simplify the concept of browser fingerprints, enabling you to quickly understand this topic and effectively protect your personal privacy and account security.
What is Canvas Fingerprinting
In today's digital era, as technology continues to advance, many websites utilize various methods to identify and track users' online activities. One commonly used technique is known as Canvas fingerprinting.
Canvas fingerprinting is a recognition method that captures distinctive device characteristics through the Canvas element in HTML5. The Canvas element is an HTML5 tag used for drawing graphics and images on a web page. It enables the dynamic generation, display, and modification of images using JavaScript code. Canvas fingerprinting exploits the subtle variations in how browsers render the Canvas element, resulting in the creation of a unique fingerprint.
How Does Canvas Fingerprinting Work?
Here are the steps websites take to obtain user fingerprints through Canvas fingerprinting technology:
Step 1: Creating a Hidden Canvas Element
The website creates a hidden Canvas element, which can be used to draw graphics, text, and images. It's like having an invisible canvas placed within the webpage.
Step 2: Drawing Graphics
Using the Canvas API, the website draws various graphics or shapes on this hidden canvas, such as lines, rectangles, circles, or text. Colors and transformations can also be applied to these patterns. It's like to using different colors and shapes to create visuals on the unseen canvas.
Step 3: Retrieving Canvas Data
Once the drawing is finished, the image data is recorded as pixels, where each pixel holds a specific value. The website uses the Canvas API and JavaScript to retrieve the numerical values of these images.
It's similar to converting the canvas graphics into numeric data, effectively recording the colors of each pixel on the canvas.
Step 4: Generating a Unique Canvas Fingerprint
The website feeds these color values into an algorithm that performs intricate calculations to generate a distinct identifier. Due to variations in the user's operating system, browser, GPU, drivers, and the rendering process, slight disparities arise during shape drawing. These minor differences lead to the creation of distinct identifiers (Hash values). As a result, each user can possess a unique Canvas fingerprint.
Step 5: Storing and Comparing Fingerprints
Finally, the website stores this unique fingerprint on its server for future use. When the user revisits the website, it captures the user's Canvas data again, recalculates the fingerprint, and then compares it to the previously stored fingerprint to recognize the user.
In summary, through the 5 steps, the website can use Canvas to capture the user's fingerprint for the purpose of identification and tracking. It's similar to preparing a canvas on the website, drawing graphics with various colors, shapes, and parameters, carefully observing the subtle differences in each pixel, and ultimately generating a unique fingerprint string to represent the patterns on the canvas.
Use Cases for Canvas Fingerprinting
Canvas fingerprinting has gained widespread application due to several key factors:
Device hardware and browser environment variations: Each device's hardware and browser environment are unique, including factors such as graphics cards, operating systems, and browser versions. These factors can result in slight variations in the Canvas element's drawing operations. For example, different devices may have subtle differences in rendering colors, text rendering, gradient effects, and more.
Randomness in drawing operations: When executing Canvas drawing operations, there is a certain level of randomness due to device and browser differences. For instance, the same drawing operation may yield slightly different results on different devices, or even different browser versions on the same device.
Difficulty in emulation and tampering: Canvas fingerprints are generated based on the differences in device and browser environments, which are typically challenging to emulate or tamper with. While advanced hackers may attempt to simulate or manipulate fingerprints, it is generally difficult for most users.
Therefore, Canvas fingerprinting can be applied in the following areas:
Account security: Websites can detect user account behavior and take prompt action to limit account access in the event of malicious attacks.
Customized advertising: Advertisers can provide targeted ad content based on user fingerprint information, thereby increasing ad click-through rates.
Fair gaming: Gaming platforms can identify devices with similar or identical fingerprints to exclude interference from cheating devices, ensuring the fairness of games.
How to Aovid Canvas Fingerprinting
We all know that disabling cookie functionality can prevent cookie tracking. However, disabling canvas tracking is not as straightforward.
If we completely disable the Canvas element, what would happen?
The webpages you visit may not load properly since you are blocking the normal display of canvas elements. Additionally, from the perspective of the website, while every other user has canvas elements displayed, you stand out by not having them, which may raise suspicions by the website.
According to BrowserScan's research on privacy and security, in most cases, "Replace" solutions are preferable to "Disable" solutions. If a website requires user data, users can use randomly generated canvas fingerprints as substitutes for their real canvas fingerprints. This allows the website to obtain data while preserving privacy and security, achieving two goals at once.
There are plugins available in the market specifically designed to generate canvas fingerprints, but their effectiveness and security are still under observation. In most cases, using a fingerprint browser is the most convenient option, as it can mask the real device's canvas fingerprint almost entirely.
The BrowserScan detection results include over 50 attributes, one of which is the Hash value of the canvas fingerprint. If you are currently using a fingerprint browser, you can visit BrowserScan for detection and compare the Canvas Hash obtained from browsers such as Chrome, Firefox, and Safari.
Your device's Canvas Hash
Summary
Canvas fingerprinting remains a widely used fingerprinting technique, with both advantages and disadvantages. It is important to remain vigilant and understand its potential impact, and choose privacy protection measures according to individual needs and weighing the pros and cons.
Pros:
Accurate identification: Canvas fingerprinting technology can generate unique digital fingerprints, accurately identifying and tracking devices, providing a foundation for personalized services and security verification.
Enhanced security: Canvas fingerprinting technology can be used to prevent fraud and malicious activities, enhancing the security of systems and applications.
Personalized content: Canvas fingerprinting technology can be used to deliver personalized content, catering to users' demands for personalized experiences.
Cons:
Privacy invasion: Canvas fingerprinting technology may collect and analyze information about users' devices, raising concerns about personal privacy.
Risk of misidentification: Due to the slight variations in drawing operations that can arise from various factors related to devices and browsers, there is a risk of misidentification with Canvas fingerprinting technology, leading to incorrect identification or false positives for legitimate users.
Read Also
Browser Fingerprinting Guide for Beginners
10 Browser Fingerprints to Know in 5 Minutes
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