Cloudflare has announced the open beta of Turnstile, an invisible alternative to CAPTCHAs that anyone can use on their website by calling a simple API. It hopes that Turnstile will allow you to get onto websites quicker and in a less frustrating way than solving a CAPTCHA puzzle or entering a bunch of letters and numbers.
Instead of the user having to interact with a simple puzzle, the Turnstile system uses non-intrusive challenges based on telemetry and client behaviour during a session. Cloudflare said that as Turnstile challenges become less effective, they will be rotated out for new ones, keeping malicious actors at bay. Explaining how it works in a bit more detail, Cloudflare said:
Turnstile also includes machine learning models that detect common features of end visitors who were able to pass a challenge before. The computational hardness of those initial challenges may vary by visitor, but is targeted to run fast.”