Editing CAPTCHA (section)

{{Short description|Test to determine whether a user is human}}
{{Pp-vandalism|small=yes}}
{{Cleanup rewrite|date=November 2022|It feels like an essay criticising CAPTCHA|section=no}}
{{Use dmy dates|date=October 2022}}
[[File:captcha.jpg|upright=1.35|thumb|This CAPTCHA ([[reCAPTCHA v1]]) of "smwm" obscures its message from computer interpretation by twisting the letters and adding a slight background color gradient.]]

'''Completely Automated Public Turing Test to tell Computers and Humans Apart''' ('''CAPTCHA''') ({{IPAc-en|ˈ|k|æ|p|.|tʃ|ə}} {{respell|KAP|chə}}) is a type of [[challenge–response authentication|challenge–response]] [[turing test]] used in [[computing]] to determine whether the user is human in order to deter bot attacks and spam.<ref>{{Cite web|title=The reCAPTCHA Project – Carnegie Mellon University CyLab|url=https://www.cylab.cmu.edu/partners/success-stories/recaptcha.html|url-status=dead|archive-url=https://web.archive.org/web/20171027203659/https://www.cylab.cmu.edu/partners/success-stories/recaptcha.html|archive-date=2017-10-27|access-date=2017-01-13|website=www.cylab.cmu.edu}}</ref>

The term was coined in 2003 by [[Luis von Ahn]], [[Manuel Blum]], Nicholas J. Hopper, and [[John Langford (computer scientist)|John Langford]].<ref name="abhl" /> It is a [[contrived acronym]] for "Completely Automated Public [[Turing test]] to tell Computers and Humans Apart."<ref>{{Cite web |title=What is CAPTCHA? |url=https://support.google.com/a/answer/1217728 |url-status=live |archive-url=https://web.archive.org/web/20200806173938/https://support.google.com/a/answer/1217728 |archive-date=6 August 2020 |access-date=2022-09-09 |website=Google Support |publisher=Google Inc. |quote=CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart) is a [...]}}</ref> A historically common type of CAPTCHA (displayed as [[reCAPTCHA v1]]) was first invented in 1997 by two groups working in parallel. This form of CAPTCHA requires entering a sequence of letters or numbers from a distorted image. Because the test is administered by a computer, in contrast to the standard Turing test that is administered by a human, CAPTCHAs are sometimes described as [[reverse Turing test]]s.<ref>{{Cite journal |last=Mayumi Takaya |last2=Yusuke Tsuruta |last3=Akihiro Yamamura |date=2013-09-30 |title=Reverse Turing Test using Touchscreens and CAPTCHA |url=http://isyou.info/jowua/papers/jowua-v4n3-3.pdf |journal=Journal of Wireless Mobile Networks, Ubiquitous Computing, and Dependable Applications |volume=4 |issue=3 |pages=41–57 |doi=10.22667/JOWUA.2013.09.31.041|archive-date=22 August 2017|archive-url=https://web.archive.org/web/20170822001858/http://isyou.info/jowua/papers/jowua-v4n3-3.pdf|url-status=live}}</ref>

Two widely used CAPTCHA services are [[Google]]'s [[reCAPTCHA]]<ref>{{Cite web |title=What is reCAPTCHA? –?reCAPTCHA Help |url=https://support.google.com/recaptcha/answer/6080904?hl=en |access-date=2023-07-20 |website=support.google.com |archive-date=20 July 2023 |archive-url=https://web.archive.org/web/20230720192427/https://support.google.com/recaptcha/answer/6080904?hl=en |url-status=live }}</ref><ref>{{Cite web |last=Sulgrove |first=Jonathan |date=2022-07-07 |title=reCAPTCHA: What It Is and Why You Should Use It on Your Website – TSTS |url=https://www.tsts.com/blog/recaptcha-what-it-is-and-why-you-should-use-it-on-your-website/ |access-date=2022-11-10 |website=Twin State Technical Services |language=en-US |archive-date=10 November 2022 |archive-url=https://web.archive.org/web/20221110020410/https://www.tsts.com/blog/recaptcha-what-it-is-and-why-you-should-use-it-on-your-website/ |url-status=live }}</ref> and the independent hCaptcha.<ref>{{Cite web |title=Websites using hCaptcha |url=https://trends.builtwith.com/websitelist/hCaptcha |access-date=2022-11-10 |website=trends.builtwith.com |archive-date=10 November 2022 |archive-url=https://web.archive.org/web/20221110020408/https://trends.builtwith.com/websitelist/hCaptcha |url-status=live }}</ref><ref>{{Cite web |title=hCaptcha – About Us |url=https://www.hcaptcha.com/about |access-date=2023-07-20 |website=www.hcaptcha.com |language=en |archive-date=20 July 2023 |archive-url=https://web.archive.org/web/20230720192429/https://www.hcaptcha.com/about |url-status=live }}</ref> It takes the average person approximately 10 seconds to solve a typical CAPTCHA.<ref>{{cite book|last1=Bursztein|first1=Elie|last2=Bethard|first2=Steven|last3=Fabry|first3=Celine|last4=Mitchell|first4=John C.|last5=Jurafsky|first5=Dan|title=2010 IEEE Symposium on Security and Privacy |chapter=How Good Are Humans at Solving CAPTCHAs? A Large Scale Evaluation |access-date=March 30, 2018|chapter-url=https://web.stanford.edu/~jurafsky/burszstein_2010_captcha.pdf|year=2010|pages=399–413|doi=10.1109/SP.2010.31|citeseerx=10.1.1.164.7848|isbn=978-1-4244-6894-2|s2cid=14204454|archive-date=8 August 2018|archive-url=https://web.archive.org/web/20180808033552/https://web.stanford.edu/~jurafsky/burszstein_2010_captcha.pdf|url-status=live}}</ref> With the rising usage of AI, CAPTCHA scams are increasing and may be at risk of being circumvented.<ref>{{Cite web|url=https://it.osu.edu/news/2025/01/13/beware-fake-captcha-initiates-malware|title=Beware of Fake CAPTCHA that Initiates Malware|date=13 January 2025|website=Office of Technology and Digital Innovation}}</ref>