What is Changzhou Li Duo Verification Code?

Changzhou Li Duo verification code is a picture generated from a series of randomly generated numbers or symbols. The verification code function of Changzhou Li Duo can effectively prevent specific registered users from constantly trying to log in by using specific program cracking methods. In fact, using verification code is a popular way for many websites, such as online personal banking of China Merchants Bank and QQ community of Tencent, which all use relatively simple verification code to realize this function.