The Captcha is no longer solve the Spam
For Digital Future | September 11, 2008
For more than a decade, technology companies seeking to find a cure or vaccine against the epidemic of Spam. One such system is called CAPTCHA, acronyms in English means "Completely Automated Public Turing test to tell Computers and Humans Apart." It consists of a series of characters displayed on deformed and funds to avoid confusing their automatic recognition. They were found when opening an email account based on the Web, or when you post a comment on a blog. But this system is becoming increasingly easy to sabotage.
There are three systems used by "spammers" to overcome the Captcha:
- The first is the simplest of all: it is to pay a person to be resolved. An article in the journal ZDNet U.S., "Inside CAPTCHA solving India's economy," reveals the plot developed in countries such as India to recruit people to solve CAPTCHA at a rate of two dollars for every thousand Captcha. This system, called brute force, but the actual demand intelligence to write well the key.
- Another approach is to offer an economic incentive not to change the resolution of CAPTCHA. For example, a web page where users have access to photographs of a woman with something less clothes each time if at every step to resolve the CAPTCHA request, which comes precisely from the site where the spammer seeks to enter.
- The third option is the use of automated algorithms for character recognition, improved to reach even recognize capricious usual deformations in the captcha. In this case you do not need a high accuracy: the mathematics used in the world of "spammers", capable of delivering 100 thousand attempts per day, makes a mere 15 percent efficiency in the resolution of a system already determined CAPTCHA productive.
Per a escriure aquest article I extret Information on ZDNET i Blog d'Enrique Dans
Topics: Internet Security |
- ReCaptcha, antispam and digitizer texts
- The best systems in order to prevent spam e-mail addresses public
- Avoiding spam
- Computer viruses in mobile phones
- Iframe attack to Digital Future and its solution
