A new graphical password scheme against spyware by using CAPTCHA.

Haichang Gao Xiyang Liu A new graphical password scheme against spyware by using CAPTCHA. 2009 SOUPS http://doi.acm.org/10.1145/1572532.1572560 conf/soups/2009 db/conf/soups/soups2009.html#GaoL09