CAPTCHAs are those now ubiquitous challenges you encounter to prove that you’re a human and not a bot when you go to log in to many websites. As a computer scientist, I see CAPTCHAs as an effective ...

(The Conversation is an independent and nonprofit source of news, analysis and commentary from academic experts.) Tam Nguyen, University of Dayton (THE CONVERSATION) CAPTCHAs are those now ubiquitous ...