Pligg CMS CAPTCHAs
Currently Pligg includes 4 different CAPTCHA methods through the official CAPTCHA module. All 4 of these options come pre-configured and ready for use. When you install Pligg CMS for the first time it will automatically enable a CAPTCHA for you. Below are descriptions for each form of CAPTCHA currently included in this module.
The new default CAPTCHA for Pligg 2.0.0 and above is Solve Media, powered by SolveMedia.com. Pligg uses this CAPTCHA out of the box because it actively fights spam by presenting users who it suspects as being bots with more difficult questions.
The biggest downside to the Solve Media method is that it often requires users to watch a brief video before they are provided with a CAPTCHA answer. Fair notice: Pligg LLC makes a very small amount of money from the Solve Media CAPTCHA by using a special API key. Without this default API, you are required to generate your own Solve Media API key and enter it on your own. You can do all of this and benefit from Solve Media’s affiliate program.
To archive human knowledge and to make information more accessible to the world, multiple projects are currently digitizing physical books that were written before the computer age. The book pages are being photographically scanned, and then transformed into text using “Optical Character Recognition” (OCR). The transformation into text is useful because scanning a book produces images, which are difficult to store on small devices, expensive to download, and cannot be searched. The problem is that OCR is not perfect.
reCAPTCHA improves the process of digitizing books by sending words that cannot be read by computers to the Web in the form of CAPTCHAs for humans to decipher. More specifically, each word that cannot be read correctly by OCR is placed on an image and used as a CAPTCHA. This is possible because most OCR programs alert you when a word cannot be read correctly.
But if a computer can’t read such a CAPTCHA, how does the system know the correct answer to the puzzle? Here’s how: Each new word that cannot be read correctly by OCR is given to a user in conjunction with another word for which the answer is already known. The user is then asked to read both words. If they solve the one for which the answer is known, the system assumes their answer is correct for the new one. The system then gives the new image to a number of other people to determine, with higher confidence, whether the original answer was correct.
The WhiteHat CAPTCHA is similar to the Pligg default CAPTCHA. It is based on the work of http://www.white-hat-web-design.co.uk.
The math question CAPTCHA asks a user to solve a simple math formula. You specify a 2 number ranges for the CAPTCHA to pull a random number from using the Pligg configuration page. The end result would look something like this:
4 + 4 =
Using the example above, the CAPTCHA is expecting the user to enter the value “8″ into the CAPTCHA field. This CAPTCHA method assumes that a computer won’t try to solve the math question. It is much less secure than randomly generated images because it can be read by computers much easier. At the same time it is partially more user friendly because a user doesn’t have to decipher a partially scrambled alphanumeric image. Math is also a universal language that can be understood by most users.