What is Captcha?
In a CAPTCHA test (an acronym for "Completely Automated Public Turing test to tell Computers and Humans Apart," also sometimes spelled in lowercase), an image of letters is dynamically generated. The letters, because they're part of an image and not text (e.g. Text that you could cut and paste), are difficult for a spambot or other computer program to read. Yet, a person has little trouble reading the letters in a captcha image.
Using a captcha test on a website is a great way to ensure, for instance, that a person and not a spambot is filling out a web form. Also, a captcha can make it difficult for a person to continuously resubmit form information and overwhelm the form's purpose.
CAPTCHAs are used to prevent automated software from performing actions which degrade the quality of service of a given system, whether due to abuse or resource expenditure. CAPTCHAs can be deployed to protect systems vulnerable to e-mail spam, such as the webmail services of Gmail, Hotmail, and Yahoo! Mail.
Moni Naor was the first person to theorize a list of ways to verify that a request comes from a human and not a bot. The term CAPTCHA (for Completely Automated Public Turing Test To Tell Computers and Humans Apart) was coined in 2000 by Luis von Ahn, Manuel Blum, Nicholas Hopper and John Langford of Carnegie Mellon University.
See here a tutorial about how to enable/disable CAPTCHA on your site: www.modwest.com
In a CAPTCHA test (an acronym for "Completely Automated Public Turing test to tell Computers and Humans Apart," also sometimes spelled in lowercase), an image of letters is dynamically generated. The letters, because they're part of an image and not text (e.g. Text that you could cut and paste), are difficult for a spambot or other computer program to read. Yet, a person has little trouble reading the letters in a captcha image.
Using a captcha test on a website is a great way to ensure, for instance, that a person and not a spambot is filling out a web form. Also, a captcha can make it difficult for a person to continuously resubmit form information and overwhelm the form's purpose.
CAPTCHAs are used to prevent automated software from performing actions which degrade the quality of service of a given system, whether due to abuse or resource expenditure. CAPTCHAs can be deployed to protect systems vulnerable to e-mail spam, such as the webmail services of Gmail, Hotmail, and Yahoo! Mail.
Moni Naor was the first person to theorize a list of ways to verify that a request comes from a human and not a bot. The term CAPTCHA (for Completely Automated Public Turing Test To Tell Computers and Humans Apart) was coined in 2000 by Luis von Ahn, Manuel Blum, Nicholas Hopper and John Langford of Carnegie Mellon University.
See here a tutorial about how to enable/disable CAPTCHA on your site: www.modwest.com
