SKI+ is an end-to-end message encryption and decryption APP The encryption and decryption calculation of the message is completed by the mobile terminal. The server side cannot know the encryption and decryption details. Therefore, it is a message system that is more user-friendly. The "sensitive capitals" used include: . MobilePhone Number (phone number)     The phone number is only used for SMS verification and registration, and will not be used for any other purpose. The "sensitive privacy