Towards human interactive proofs in the text-domain using the problem of sense-ambiguity for security

Abstract

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. © Springer-Verlag 2004.