Yep, this is a pretty simple CAPTCHA picked to illustrate a concept for teaching purposes. But more complex CAPTCHA images don't necessarily make anything more

Yep, this is a pretty simple CAPTCHA picked to illustrate a concept for teaching purposes. But more complex CAPTCHA images don't necessarily make anything more secure depending on how the whole system works. In fact, one of the most effective attacks against Google's ReCAPTCHA is more simple than anything in this article - you just request the audio version of the captcha, feed it to Google's own Speech Recognition API (or a competitor), and give Google back it's own result [1] [1] https://github.com/eastee/rebreakcaptcha https://github.com/eastee/rebreakcaptcha