Chimera CAPTCHA: A Proposal of CAPTCHA Using Strangeness in Merged Objects

  • Masahiro Fujita
  • Yuki Ikeya
  • Junya Kani
  • Masakatsu NishigakiEmail author
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 9190)


In this paper, we propose “Chimera CAPTCHA” that requests users to select only a chimera object, merged from two 3D objects, in a question image, which consists of some 3D objects and the chimera object. The Chimera CAPTCHA is easy for humans to solve because chimera objects, whose appearance are different from ones judged by common sense, cause a feeling of strangeness. Usability survey suggests that the correct response rate is 90.5 % and the average response time is about 5.7 s. In addition, the CAPTCHA system is able to generate questions countlessly and easily by using 3DCG technologies. We also describe threats to its security.


CAPTCHA A feeling of strangeness Automatic generation 3DCG 


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Copyright information

© Springer International Publishing Switzerland 2015

Authors and Affiliations

  • Masahiro Fujita
    • 1
  • Yuki Ikeya
    • 1
  • Junya Kani
    • 1
  • Masakatsu Nishigaki
    • 1
    Email author
  1. 1.Graduate School of InformaticsShizuoka UniversityHamamatsuJapan

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