It tests whether your mouse movement looks human--we're really bad at things like moving in straight lines, so it's pretty evident from a mouse movement log whether you're a human or a simple bot. It also takes a bunch of auxiliary browser/environment data into account. It's not perfect, but it's complicated enough to defeat to provide fine protection against cheap spam.

Proof of work, which becomes computationally expensive to scale, along with other heuristics based on your browser and page interaction. I believe it's less about clicking the box and what happens after you've clicked the box.

https://blog.cloudflare.com/turnstile-private-captcha-alternative/

TL:DR cloudflare made a new recaptcha which does some complex math and other stuff on your browser, which done once has no noticable effect but if someone were to scrape websites at an absurd speed it slows everything down significantly.

this is not only cool because you don't have to manually solve the captcha, but also because it allows for low-speed scraping to be feasible, with tools like flaresolverr

Theres a few answrs to this

1. It uses your movements before this to determine whether it feels like your a bot or not
2. It makes you wait, the biggest issue with bots is they may try to log in say 50 different passwords for example, so if it takes 5 seconds to do each one it makes boting multiple acounts not worth it.
3. Google uses catchphas with images to choose. They use this to train their own AI or data to sell

These type of “captchas” look at your browsing behavior. It is sort of a “trade secret” of what it looks for, but it might be screen resolution, mouse behavior, cookies, OS, time to click, etc. Anything a website has access to that would look different from a bot.

Clicking a check box might not be the definite quality that makes you a human, but pondering on the meaning of things and questioning your humanity with a curious introspective state of mind - THAT what makes you a human! I'm proud of you, fellow human!

I always fail Cloudflare captchas because I'm clicking it with Vimium-C lol. I hate captchas for making me reach for my mouse. It also seems like a genuine accessibility issue if people who cannot use a mouse can't pass a captcha.

I've found that Google's reCAPTCHA has also started rejecting me no matter what I do. I think it might be because my IP address is a VPN, but that's pretty stupid; if I can pass the test by clicking the squares why not let me in?

it also sees your mouse movements on your way to that box.

I'm sorry, but "now"? This has been a thing for at least half a decade. Are you Encino Man? Did you just wake up?

Cloudflare has a bot score. Depending on how sus your bot score is you can use several different levels of verification. The checkbox you refer to is kind of in the middle. There is also a more complicated intrusive captcha and a totally transparent javascript. It’s a pretty slick system.

Humans have mouse movement that, on August 8, 2024, are very hard to reproduce. But just like regular captchas we are just teaching computers to do the same thing.

Others mention the mouse motion, and monitoring your other traffic to similar sites. When it shows the checkbox, it has already determined you are probably human. If you had suspicious activity, they will give you more advanced tests instead of just a checkbox.

Cloudflare knows almost everything done from your IP address because they're used by the majority of websites. And some websites are using a cloudflare signed TLS certificate so if cloudflare wants, can see the content of the communication instead of an encrypted package

So they know if you have a human behavior (visiting many different websites at human speed and having rests during sleeping time) or if you have a bot behavior (sending millions of requests to the same endpoint at superhuman speeds)

I've been told that it's analyzing your behavior from right before you click the button

Clicking the button doesn't proof that you are a human. All the checks happen way before you even click the button (or sometimes even before visiting the website). Google also offers a similar button for their users and since cloudflare is also used on almost any website, they have a lot of data about you. They check your cookies, browser agent, device, settings, your IP address, if you use a VPN or proxy, etc. If you visited other cloudflare websites in the past with the same device or IP, and so on. So they know you and your device way before you even click the button. This is also the reason why you sometimes see a robot arm (made of Lego) clicking the button, and is still recognized as human. But as soon as you use a different IP address or a VPN (or even use a shared IP address, like in your company's network) you have to solve CAPTCHAs. Of course they also check mouse movement, but this is only one part of many checks.

Basically bots would automatically click on it, teleporting the cursor to the very center of the button. They will do this within exact milliseconds of the page loading.

Humans read something on the site, then find the banner, and move the cursor over to it, confirm that the cursor is somewhere on the button, and then click it.

It's not just the button, it's the before the button that determines you're a bot or not.

Beats me. I have a script that clicks all those boxes for me.

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