CAPTCHA Design: Color, Usability, and Security.

Ahmad Salah El Ahmad Jeff Yan Wai-Yin Ng

Published in: IEEE Internet Comput. (2012)

Keyphrases

design process
user experience
color images
software architecture
case study
access control
building blocks
privacy preserving
computer aided
functional requirements
information systems
image sequences
design decisions
design issues
user interface design
heuristic evaluation