Microsoft Word - captcha-www2009-FINAL.docWhat’s Up CAPTCHA? A CAPTCHA Based On Image Orientation Rich Gossweiler Google, Inc. 1600 Amphitheatre Parkway Mountain View, CA 94043 rcg@google.com Maryam Kamvar Google, Inc. 1600 Amphitheatre Parkway Mountain View, CA 94043 mkamvar@google.com Shumeet Baluja Google, Inc. 1600 Amphitheatre Parkway Mountain View, CA 94043 shumeet@google.com ABSTRACT We present a new CAPTCHA which is based on ident
