Mitigating Dictionary Attacks with Text-Graphics Character Captchas.

Chanathip Namprempre Matthew N. Dailey Mitigating Dictionary Attacks with Text-Graphics Character Captchas. 179-186 2007 90-A IEICE Transactions 1 http://dx.doi.org/10.1093/ietfec/e90-a.1.179 db/journals/ieicet/ieicet90a.html#NamprempreD07