It is a well documented fact that, for human readers, familiar text is more legible than unfamiliar text. Current-generation computer vision systems also are able to exploit some ...
We present Asirra (Figure 1), a CAPTCHA that asks users to identify cats out of a set of 12 photographs of both cats and dogs. Asirra is easy for users; user studies indicate it c...
Jeremy Elson, John R. Douceur, Jon Howell, Jared S...
The ASIRRA CAPTCHA [6], recently proposed at ACM CCS 2007, relies on the problem of distinguishing images of cats and dogs (a task that humans are very good at). The security of AS...
: Rock art, human-made markings on stone, is an important cultural and the earliest expression of abstract thinking. While there are tens of millions of photographs of rock art in ...