In 2017 I was able to decrypt the video (for test only) too, but without breaking Arxan's whitebox implementation. I was able to retrieve all the state needeed to regenerate the keystream, then patched google's shaka packager to use this keystream instead of the one derived from the original key (which I didn't have) and the decryption was successful. But that was a manual process just for test - you'd need to load a special kernel module, launch chromium, then start the video, and so on... But that was in 2017, I guess it'd be harder to do now