μcaptcha is a math handwriting captcha scheme for touch-capable devices. Instead of entering text with a keyboard, you just retype a mathematical expression shown on a web canvas. μcaptcha belongs to the set of protocols called HIPs (Human Interactive Proofs), which allow a person to authenticate as belonging to a select group; e.g., human as opposed to machine, adult as opposed to a child, etc.
μcaptcha allows you protect your online forms from illegitimate access or abuse. Furthermore, as a byproduct of solving μcaptchas, a valuable labeled dataset of online handwritten math expressions is collected. μcaptcha is thus channeling the users' effort into creating valuable resources for machine learning.
Learn how μcaptcha works