Reports Of The Death Of CAPTCHAs May Be Premature

Completely Automated Public Turing test to tell Computers and Humans Apart (CAPTCHAs) are not quite as dead as I'd thought.  In order to be immune to bots CAPTCHAs have become so difficult that I find it difficult to prove I'm a human with some of the images they ask me to identify.  I'd assumed that they were becoming so user unfriendly that they had effectively lost the battle in their fight with the bot armies.

However, a paper I've just been reading might have the answer. With the great title "No Bot Expects the Deep CAPTCHA!" it presents a new technique called DeepCAPTCHA which abandons the ever increasing amount of general adversarial noise being added to CAPTCHA images to introduce a concept called "immutable adversarial noise" (IAN).

We've known for some time the CAPTCHAs are vulnerable to automated systems.  I wrote about some work my colleagues had done on just this problem in various banking systems back in 2012.