Why did Hunan Institute of Education send SMS verification code?

For the first time, it is stipulated that candidates must bind the password card or mobile phone number when logging in to the "Hunan College Entrance Examination Information Management Platform (Candidate Edition)". Binding a password card or a mobile phone number means binding the candidate's information with the password card or mobile phone number. In the future, candidates must use the password of the password card or the SMS verification code received by the mobile phone for security verification when saving their volunteers and resetting their passwords.

If the examinee is only bound with a password card, enter the password of the password card for identity verification; If the candidate is only bound to the mobile phone number, enter the SMS verification code received by the mobile phone for identity verification; If the examinee is bound with the password card and mobile phone number at the same time, he can choose either method for security verification.