Article dans wikipedia

Extrait : " CAPTCHAs are used to prevent bots or automated programs from using various types of computing services or collecting certain types of sensitive information. Applications include preventing bots from taking part in online polls, registering for free email accounts (which may then be used to send spam) and collecting email addresses. CAPTCHAs can prevent bot-generated spam by requiring that the (unrecognized) sender pass a CAPTCHA test before the email message is delivered, but the technology can also be exploited by spammers by impeding OCR detection of spam in images attached to email messages. CAPTCHAs have also been used to prevent people from using bots to assist with massive downloading of content from multimedia websites. They are used in online message boards and blog comments to prevent bots from posting spam links as a comment or message."

C'est un test de défi-réponse utilisé en informatique, pour s'assurer qu'une réponse n'est pas générée par un ordinateur. L'acronyme « CAPTCHA » est basé sur le mot capture, et vient de l'anglais completely automated public Turing test to tell computers and humans apart.

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