Lecture 7

2009-12-09

CAPTCHAs: telling humans and computers apart automatically.  Turing tests, reverse Turing tests, types of CAPTCHAs, text-based CAPTCHAs, methods for breaking text CAPTCHAs, visual CAPTCHAs, implicit CAPTCHAs, visual passwords.

Lecture

• CAPTCHAs View

Reading

• CAPTCHAs View
• Scattertype View
• Baffletext View
• breaking text-based CAPTCHAs View
• reCAPTCHA View
• Usability of Visual PINs View
• Security of Visual CAPTCHAs View