subject: Does Your Website Need Some Captcha? [print this page] Many owners of corporate websites have faced this problem: You want to be a feature on its website for visitors to post comments without opening the door to spammers.
Make your e-mail on your site are generally an invitation for spam. automated programs known as "bots" Finally, the analysis of your website and analyze your e-mail from the rest of the source code and use it for purposes other than known what you wanted.
There are some tricks and techniques to "cloak" your e-mail address, so that these robots are not easy to find. One method that I used to include Javascript in my web page, which pieces together the e-mail when the page is displayed to the user. In this method, there is not a valid email address in the source of the page itself. It seems to work fairly well, but certain "junk mail" works still get through.
Another method is not appropriate to your e-mail to all on your site, but a "make assessment" or "Golden Book" as type ", where visitors can leave comments and then submit with the form on the website. This allows the e-mail from the website, complete with a server script that activates when the visitor the form is submitted. In general, this script then formats and sends a message to the owner of the site of an e-mail program on the server itself using the actual e-mail address in the script or a database is not encrypted and is for visitors outside.
These forms of feedback to help that, but it is still possible to automate the entry of these forms, as a result receive the spam. It raises the bar, so to say that automate difficult but not impossible.
A better way to use these forms with CAPTCHA website. You probably have seen in use on large web sites with pages of registered users. Before submitting the form, the user is required to read the distorted letters on the screen and saves it as verification. The idea is that the distorted letters or characters created by computer programs, so that the web form submitted, can be interpreted automatically validated as a human rather than automated programs.
CAPTCHA is an acronym for "completely automated public Turing test to tell Computers and Humans Apart." The term is a registered trademark of Carnegie Mellon University and began in 2000, so it is not too long. In fact, a CAPTCHA is a program that different quality types of tests that most humans can pass but computer programs can generate can not happen. The best known to the common distorted letters and numbers is to test. A CAPTCHA is to be fully automated, without user intervention, making it a reasonable option for site owners.
Adding a CAPTCHA program on your site can validate a reliable method that the information presented is a real, living person, not an automated program. The use of CAPTCHA is far more widespread and not only on the more important sights. Many examples of the integration of the site can be found per site in popular programming languages.
Some good resources to start CAPTCHA is available at:
