Definitions for CAPTCHA

This page provides all possible meanings and translations of the word CAPTCHA

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  1. CAPTCHA(Noun)

    A distorted image of letters and numbers used to prevent automated use of websites.

    I find CAPTCHAs very difficult to read.

  2. CAPTCHA(Noun)

    Anything that a human must do to prove that they are not a computer.

  3. Origin: Coined by a team of researchers at Carnegie Mellon University in 2000 as a loose

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    A CAPTCHA is a type of challenge-response test used in computing to determine whether or not the user is human. The term was coined in 2000 by Luis von Ahn, Manuel Blum, Nicholas J. Hopper of Carnegie Mellon University, and John Langford of IBM. A common type of CAPTCHA requires that the user type the letters of a distorted image, sometimes with the addition of an obscured sequence of letters or digits that appears on the screen. Because the test is administered by a computer, in contrast to the standard Turing test that is administered by a human, a CAPTCHA is sometimes described as a reverse Turing test. This term is ambiguous because it could also mean a Turing test in which the participants are both attempting to prove they are the computer.

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"CAPTCHA." STANDS4 LLC, 2015. Web. 2 Apr. 2015. <>.

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