Protect associated files in app

Question

I am making an app which shows learning videos for kids. The videos used in this app are stored in an external SD card . I want to know how can I encrypt these files so that no one can access these video files. My idea is to encrypt the video files and decrypt these video files dynamically, ie, when one is accessing a particular file, then only that video will decrypt and played but not stored. How can I achieve this? Has anyone did this ? Any better ideas ?

Answer 1

There is no need to encrypt files that are used by your app. Every app has it's own private directory where you can store files that cannot be accessed by other apps or the user ( link ).

Without having more information about your app it's hard to judge but in general it's better to save video's in a cache directory ( link ). This cache directory is also private.