Offline authentication is a method of automatically authenticating without internet connection. User installs the memory card, and authentication is automatically performed when the app is first run. You can not play content on other storage media by copying, moving, etc., or you can make the storage media available only to the first authenticated device.
It is a method to authenticate through the serial number that the user has been given, and it is necessary to access online at the time of authentication (one-time only). After authentication, you can freely use content in offline environment. If you are looking for a content business in a poor network environment, this is a better service.
If content expiration is set, you will not be able to play content that has expired. Also, if you manipulated the time on your device, you can not play content that has expired or has been out of date in offline environment.