How to display encrypted resources in WebView?

Question

Mobile development

Good afternoon.
A somewhat unusual problem arose. The mobile application has a WebView in which you need to show a page with pictures. But the fact is that pictures on a mobile device must be stored in encrypted form. It seems to me that in WebView it is somehow necessary to replace the file reading function in order to transparently decrypt it on the fly. But it is not clear how to do this, and whether this is even possible.
Mobile platforms of interest: iOS, Android, Windows 8.

Answer 1

Under Android, I did this, in the sqlite database of the application I stored the pictures in encrypted form. Before displaying information, I decoded the picture, converted it to base64, generated the page code programmatically and slipped the WebView

byte[] bb;
...
String test =Base64.encodeBytes(bb);
String html = "<img src=\"data:image/jpeg;base64,"+test+"\" />";

Answer 2

Public API is very unlikely to succeed.
Although it seems like it was somehow possible to intercept all NSURLConnection, I would search on this topic