  As a result of continuing advances in computer capabilities, it is becoming
increasingly difficult to distinguish between humans and computers in the
digital world. We propose using the fundamental human ability to distinguish
between things that are aesthetically pleasing and those that are not as the
basis of a method to verify that a communicating party is human. We discuss one
possible implementation of this notion to develop a new CAPTCHA, the Aesthetic
CAPTCHA, which we compare with widely used CAPTCHAs. Our initial analysis shows
that, at least in theory, Aesthetic CAPTCHAs offer advantages over other
schemes in terms of satisfying the full range of CAPTCHA requirements. More
generally, using human aesthetic judgement adds a possible new dimension to the
future design of Turing tests.
