In the online banking system, the user's identity authentication depends on the multiple guarantees of encryption mechanism, digital signature mechanism and user login password based on RSA public key cryptosystem. The bank checks the user's digital signature and login password, and the user's identity can only be confirmed after all of them pass. The unique identity of the user is the "digital certificate" issued by the bank. The user's login password is transmitted in the form of ciphertext, which ensures the security and reliability of identity authentication.

Authentication is the process of judging whether a user is a legitimate user. The most commonly used simple authentication method is that the system checks the user name and password entered by the user.