TEST12138

Sometimes people may browse some websites and open incognito windows while browsing. After opening, they believe that they are browsing anonymously. But is that really the case? The actual situation may be much more terrifying. It not only knows who you are but also knows what you have done, and it knows much more than you think. Some people may say, "Isn't it just through IP? Can't I just use a proxy?" What if I tell you that it can know without using IP? So how is this achieved? This is thanks to a technology called browser fingerprinting, which is a very mature technology. It can accurately identify users without cookies or login. The implementation principle is also very simple. There are so many devices in the world, but it is difficult to find two devices with the same environment. For example, IP address, browser version, browser language, browser font settings, time zone, etc. Based on this information, one or more hash values are generated, and these hash values are likely to be unique. It cannot guarantee complete non-repetition, but the uniqueness is relatively high. For example, using canvas to generate a hash, here is a simple code snippet. Normally, the generated value is 291669864. In incognito browsing, it is also 291669864. How can it be different? Change the browser or device. Drawing the same canvas, why are the generated values different? This is because different browsers, different versions of the same browser, different operating systems, and different hardware all have differences in their rendering engines. Although they draw the same canvas, there will be some imperceptible differences, which will cause differences in the generated data. This is influenced by many factors, and even installing a plugin on the browser may cause an impact, including browser settings, operating environment settings, etc. This is just one canvas. If you combine other generated hash values, just using a proxy is useless. The main purpose of this is for advertising (shopping ads, etc.) and anti-fraud (vote fraud, view count fraud, etc.). But fundamentally, it is to distinguish users, so if certain websites want to identify you, it is still very easy. However, there is something called a fingerprint browser, which allows you to switch between different fingerprints within one browser, but they are all paid services. The implementation method is also very simple, targeting different fingerprinting methods and changing the corresponding APIs.