Towards Human Interactive Proofs in the Text-Domain

Using the Problem of Sense-Ambiguity for Security
  • Richard Bergmair
  • Stefan Katzenbeisser
Part of the Lecture Notes in Computer Science book series (LNCS, volume 3225)


We outline the linguistic problem of word-sense ambiguity and demonstrate its relevance to current computer security applications in the context of Human Interactive Proofs (HIPs). Such proofs enable a machine to automatically determine whether it is interacting with another machine or a human. HIPs were recently proposed to fight abuse of web services, denial-of-service attacks and spam. We describe the construction of an HIP that relies solely on natural language and draws its security from the problem of word-sense ambiguity, i.e., the linguistic phenomenon that a word can have different meanings dependent on the context it is used in.


HIP CAPTCHA text natural language linguistic lexical word-sense ambiguity learning 


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Copyright information

© Springer-Verlag Berlin Heidelberg 2004

Authors and Affiliations

  • Richard Bergmair
    • 1
  • Stefan Katzenbeisser
    • 2
  1. 1.University of Derby in AustriaLeonding
  2. 2.Institut für InformatikTechnische Universität MünchenGarching

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