This article discusses CAPTCHAs. CAPTCHAs stand for Completely-Automated-Public-Turing-Tests- to-Tell-Humans-and-Computers-Apart. This very succinct name derives from the emergence of action operating at multiple levels but originating in individual pieces of code. As it discusses, this technology is pretty much considered standard in security and can have many widespread applications especially in commercial websites. Two elements that the paper focuses on are usability and robustness which can create fundamental issues within CAPTCHAs.
“ Some of these issues are intuitive, but some others have subtle implications for robustness (or security). A simple but novel framework for examining CAPTCHA usability is also proposed.”
It also discusses the impacts from the three main types of CAPTCHAs. These include Text-based schemes, Sound-based schemes, and Image-based schemes.
