How to encrypt video from url and save encrypted video to device's SD Card

Question

In my application I have to use of many video files. Approximately total size of all the video is 500 MB. So I have to decide at the first time when application is install and r

Answer 1

The error you are seeing has nothing to do with encryption and everything to do with file permissions. Does your app request permission to use the SD card?

Secondly, why DES? DES is usually substantially slower than AES on modern hardware, and has keys that are far too short for modern use. Also, make sure you are using a GCM, CTR or CBC mode of operation - simple ECB does not have good security properties.

Do realize that you are implementing a classic DRM scheme: anyone with access to the device and the application private directory will be able to locate the secret key file and decrypt the video, or steal the video in transit.