Electrical Engineering
      and Computer Sciences

Electrical Engineering and Computer Sciences

COLLEGE OF ENGINEERING

UC Berkeley

Image Recognition CAPTCHAs

Monica Chew and J. D. Tygar

EECS Department
University of California, Berkeley
Technical Report No. UCB/CSD-04-1333
June 2004

http://www.eecs.berkeley.edu/Pubs/TechRpts/2004/CSD-04-1333.pdf

CAPTCHAs are tests that distinguish humans from software robots in an online environment. We propose and implement three CAPTCHAs based on naming images, distinguishing images, and identifying an anomalous image out of a set. Novel contributions include proposals for two new CAPTCHAs, the first user study on image recognition CAPTCHAs, and a new metric for evaluating CAPTCHAs.


BibTeX citation:

@techreport{Chew:CSD-04-1333,
    Author = {Chew, Monica and Tygar, J. D.},
    Title = {Image Recognition CAPTCHAs},
    Institution = {EECS Department, University of California, Berkeley},
    Year = {2004},
    Month = {Jun},
    URL = {http://www.eecs.berkeley.edu/Pubs/TechRpts/2004/5256.html},
    Number = {UCB/CSD-04-1333},
    Abstract = {CAPTCHAs are tests that distinguish humans from software robots in an online environment. We propose and implement three CAPTCHAs based on naming images, distinguishing images, and identifying an anomalous image out of a set. Novel contributions include proposals for two new CAPTCHAs, the first user study on image recognition CAPTCHAs, and a new metric for evaluating CAPTCHAs.}
}

EndNote citation:

%0 Report
%A Chew, Monica
%A Tygar, J. D.
%T Image Recognition CAPTCHAs
%I EECS Department, University of California, Berkeley
%D 2004
%@ UCB/CSD-04-1333
%U http://www.eecs.berkeley.edu/Pubs/TechRpts/2004/5256.html
%F Chew:CSD-04-1333