Guangdong zhengyi verification code cannot be received.

The failure to receive Guangdong Zhengyi verification code may be caused by entering the wrong mobile phone number.

CAPTCHA (verification code) is the abbreviation of "fully automatic public testing of Totell Computer and Humansapart", and it is an open * * * fully automatic program to distinguish whether users are computers or people. It can prevent malicious password cracking, ticket brushing and forum flooding, and effectively prevent a hacker from constantly trying to log in to a specific registered user and using a specific program to violently crack. In fact, using verification code is a popular way for many websites now, and we have realized this function in a relatively simple way. This question can be generated and judged by computers, but only humans can answer it. Because the computer can't answer CAPTCHA's question, the user who answers the question can be considered as human.

The word captcha was first put forward by luis von ahn, ManuelBlum and NicholasJ J. Hopper of Carnegie Mellon University and JohnLangford 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 (OCR) 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.