I want to change the encryption of user passwords in the program, but many user passwords have been stored in the database using the original MD5 encryption.
when login, the user enters the password and then MD5 encrypts it and then compares it with the data in the database. If the data is consistent, let the user log in.
if I change the encryption method, what should I do with the original account passwords?
because of MD5, I cannot decrypt the original encrypted password and encrypt it with a new encryption method, so old users will not be able to log in