What does the shape verification code do?

It can prevent malicious password cracking, ticket brushing and forum flooding, and effectively prevent hackers from constantly trying to log in to specific registered users by using specific program brute force cracking methods.

Verification code is generally used to prevent batch registration, which is difficult for people to see, let alone machines. In order to prevent users from being automatically registered, logged in and poured water by robots, many websites adopt verification code technology. The so-called verification code is to generate a picture from a series of randomly generated numbers or symbols and add some interference to the picture.

For example, draw a few straight lines randomly, and then draw some points (to prevent OCR). Users can identify the verification code information with naked eyes, enter the form and submit it to the website for verification. Only after the verification is successful can a function be used.

Extended data:

The word captcha was first put forward by luis von ahn, Manuel Bloom, Nicholas J. Huo Po of Carnegie Mellon University and John langford of IBM in 2002.

Carnegie Mellon University tried to apply for the word to become a registered trademark, but the application was rejected on April 2, 20081. A common verification code test is to let users input characters or numbers displayed on distorted pictures. Deformation is to avoid being automatically recognized by computer programs such as optical character recognition and losing its effect.

Because this kind of test is tested by computer, not by human like the standard Turing test, people sometimes call CAPTCHA the reverse Turing test.

Baidu Encyclopedia-Picture Verification Code

Baidu Encyclopedia-Verification Code