A Machine Learning Attack against the Civil Rights CAPTCHA

Conference paper
Part of the Studies in Computational Intelligence book series (SCI, volume 570)


Human Interactive Proofs (HIPs) are a basic security measure on the Internet to avoid several types of automatic attacks. Recently, a new HIP has been designed to increase security: the Civil Rights CAPTCHA. It employs the empathy capacity of humans to further strengthen the security of a well known OCR CAPTCHA, Securimage. In this paper, we analyse it from a security perspective, pointing out its design flaws. Then, we create a successful side-channel attack, leveraging some well-known machine learning algorithms.


Correct Answer Success Ratio Turing Test Human Right Watch Basic Attack 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer International Publishing Switzerland 2015

Authors and Affiliations

  1. 1.Universidad ComplutenseMadridSpain
  2. 2.Computer Engineering DepartmentUniversidad de AlcaláMadridSpain

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