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Some web pages display something similar to this when opened, with a message like "Checking if the site connection is secure": enter image description here The process usually takes some non-trivial time, sometimes it wants me to click a Verify button, but usually it is just happy with turning the wheel for a while and then goes on to the requested page.

This occurs on many web pages.

What exactly is happening under the hood while this picture is shown to the user?

N.B. I am a backend programmer and I have just a very basic understanding about the frontend stuff.

EDIT (15.02.2024):

It seems that either FanFiction or CloudFare (whoever the wording of the message comes from) felt ashamed and changed the message! enter image description here

Honza Zidek
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1 Answers1

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with a message like "Checking if the site connection is secure":

"Review security of your connection" has nothing to do with security or connection, it means "Checking whether you're not a bot". The website is using the Cloudflare CDN service and the page is Cloudflare's "Turnstile" automated bot detection, similar to reCAPTCHA or hCaptcha.

(FanFiction.Net has strict mode enabled because it really doesn't like the idea that the stories posted therein might be archived somewhere else. Other websites might enable this feature whenever they get an influx of spam bots or such.)

The process usually takes some non-trivial time

This specific example appears to be mainly a 'proof of work' kind of check, where the system grants you access in exchange for burning some CPU time (compare with Hashcash), though it most likely also includes various other JavaScript-based bot/scraper detection that Cloudflare could think of (the exact checks are not publicly documented, as that would mostly defeat the purpose, and it's safe to assume that they also change over time).

grawity
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