If we have data stored in encrypted format by the android app (encryption key in keystore), is it possible for the app to be the only entity capable of decrypting it to do some calculations? I am talking even the app's own user can't access the decrypted data, not even when not using the app UI to access the app like hackers do.?
Exemple : server is sending encrypted data regarding a QR code for a book. The app should decryot the QR and check if it is stored inside its local data and send a response back to the server. I don't want the QR code to be humanly accessed by the app's user through the app or any other tool even though their app can.?