Thursday, November 03, 2005
Captcha - What is it?
You've seen it before, probably when buying tickets or what have you. This technology is for preventing automated ticket buying agents or "bots" from buying up all the good tickets from Ticketmaster. The technology is called CAPTCHA and stands for "completely automated public Turing test to tell computers and humans apart". It is a type of challenge-response test used in computing to determine whether or not the user is human. A common type of captcha requires that the user type the letters of a distorted and/or 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.
So this technology is being used to prevent a new type of spam, called Splogging. A splog is where an automated program creates a useless spam type blog or website and puts code on it so that google and other search programs will "index" it and think, oh, good web site, make it available to people when they are searching. Splogs have become a major problem on free blog hosts such as Google's Blogspot service. These fake blogs waste valuable disk space and bandwidth as well as pollute search engine results.
Google's Blogspot has provided me with the opportunity to use Captcha to prevent spammers from putting comments on my blog (spam comments). So, if any of you leave comments you'll be asked to enter in the captcha phrase, like on ticketmaster. And thanks for your comments....