Strong CAPTCHA
Strong CAPTCHA offers a modern take on traditional CAPTCHA that thwarts bots and CAPTCHA farms by using proprietary device intelligence to proxy and encrypt the CAPTCHA. This method is used to detect and identify bots upfront, and also ensures that the CAPTCHA can't be solved by an outsourced third party - since the device signals wouldn't match the ones used for encryption.
In other words, Strong CAPTCHA uses device- and user-specific signals to ensure CAPTCHAs are solved where they're shown - not by a bot, or by an outsourced service.
You are in control of determing when a user is prompted with Strong CAPTCHA. We recommend using Strong CAPTCHA when a user is attempting to login from a suspicious device (check out Device Fingerprinting) or about to take an action that carries a high risk of fraud (e.g. collecting a sign up bonus).