Team for Research in
Ubiquitous Secure Technology

Citation
Elie Bursztein, Matthieu Martin, John C. Mitchell. "Text-based CAPTCHA strengths and weaknesses". Proceedings of the 18th ACM conference on Computer and communications security, 2011.

Abstract
We carry out a systematic study of existing visual CAPTCHAs based on distorted characters that are augmented with anti-segmentation techniques. Applying a systematic evaluation methodology to 15 current CAPTCHA schemes from popular web sites, we find that 13 are vulnerable to automated attacks. Based on this evaluation, we identify a series of recommendations for CAPTCHA designers and attackers, and possible future directions for producing more reliable human/computer distinguishers.

Electronic downloads

• http://dl.acm.org/citation.cfm?id=2046724

• HTML

  Elie Bursztein, Matthieu Martin, John C. Mitchell. <a
  href="http://www.truststc.org/pubs/891.html"
  >Text-based CAPTCHA strengths and weaknesses</a>,
  Proceedings of the 18th ACM conference on Computer and
  communications security, 2011.

• Plain text

  Elie Bursztein, Matthieu Martin, John C. Mitchell.
  "Text-based CAPTCHA strengths and weaknesses".
  Proceedings of the 18th ACM conference on Computer and
  communications security, 2011.

• BibTeX

  @inproceedings{BurszteinMartinMitchell11_TextbasedCAPTCHAStrengthsWeaknesses,
      author = {Elie Bursztein and Matthieu Martin and John C.
                Mitchell},
      title = {Text-based CAPTCHA strengths and weaknesses},
      booktitle = {Proceedings of the 18th ACM conference on Computer
                and communications security},
      year = {2011},
      abstract = {We carry out a systematic study of existing visual
                CAPTCHAs based on distorted characters that are
                augmented with anti-segmentation techniques.
                Applying a systematic evaluation methodology to 15
                current CAPTCHA schemes from popular web sites, we
                find that 13 are vulnerable to automated attacks.
                Based on this evaluation, we identify a series of
                recommendations for CAPTCHA designers and
                attackers, and possible future directions for
                producing more reliable human/computer
                distinguishers.},
      URL = {http://www.truststc.org/pubs/891.html}
  }
  

Posted by Mary Stewart on 4 Apr 2012.
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