CAPTCHA invented back in 2000, and sincethen it has become an integral part of the Internet. Customers faced with it when you try to create an account somewhere, leave a comment, or simply by the increased activity.
How to fill in the captcha, and if you can do without it?
The word "CAPTCHA" - a Russified versionEnglish abbreviations CAPTCHA (Completely Automatic Public Turing Test to Tell Computers and Humans Apart - fully automated Turing test to differentiate between computers and humans). This is a popular tool for distinguishing between humans and robots that are trying to perform certain actions on the sites.
It is thanks to social networks is now displayed in a CAPTCHA is not cluttered army of bots.
What is CAPTCHA
The main purpose of the CAPTCHA - is the protection of thebots. Inanimate site visitors can help falsificating when voting, comments litter insults or advertising, to register hundreds of new bots users - from all of this helps protect input captures. It is assumed that the robot will not be able captan, and for a living person is not difficult, and thus save the CAPTCHA website from the invasion of robots.
The file-sharing services are forced to enter the captcha, so you can not add a link to download the program and all made by hand (and thus saw all the ads).
If you show excessive activity on the site (for example, leave too many comments in social media), you can also get to enter the captcha to prove you are not a robot.
How to enter the captcha
The most popular version of the CAPTCHA - distortedletters, numbers or combinations that need to be properly identified and entered. Some sites offer more interesting options. It may be unpretentious math problems, or simple questions, such as "4 + 6 =" or "Capital of Russia".
There are options CAPTCHA in which you needarrange pictures vertically a few pictures or just to tick. There are also exotic options. Somewhere you want to solve the problem of higher mathematics, somewhere to demonstrate knowledge of the Arabic language. Fortunately, this is not common.
For people with visual impairments is provided audiokapcha offering to determine the code by ear.
Automatic recognition of captcha
Of course, the craftsmen have come up with a lot ofways to bypass CAPTCHA. Bots can determine the correct combination code on the information contained in the code of the web page, choose the correct answer by simply sorting options.
A more sophisticated way - use software for automatic text recognition. For example, computer scientists have learned to recognize the captcha with the help of popular ABBYY FineReader.
There are also paid services for the recognition of the distorted text. But a lot of money displayed in a CAPTCHA is unlikely to succeed. 1000 correctly recognized images are no more than 20 rubles.
Pros and Cons CAPTCHA
In this protection method has a lot of enemies. Criticism is mainly connected with the inconvenience to the user. Few people like poking around in the unscrupulous characters that often have to be administered at random. Yes, and good eyesight is not conducive.
On the other hand, nothing better in terms ofease of use and quality have not yet been invented. Once this happens, the CAPTCHA will go down in history, because it is so inconvenient services without the need to use at no one will.