Hello, I'm trying to do the same thing as you.
How did you find the coliseum_mobile_vod.key ? all I can find is the adaptive.key if I save the adaptive.key and modify the video.m3u8 to point at the files and the adaptive.key ffmpeg gives the error
Code:
[crypto @ 04383620] Unable to open resource: http://nlds2.cdnak.lon.neulion.com:443/nlds_vod/coliseum/vod/2015/01/31/622/2_622_newcastleunited_hullcity_2014_h_whole_1_4500_000000.ts
[hls,applehttp @ 04381d40] Failed to open segment of playlist 0
[hls,applehttp @ 04381d40] Error when loading first segment 'http://nlds2.cdnak.lon.neulion.com:443/nlds_vod/coliseum/vod/2015/01/31/622/2_622_newcastleunited_hullcity_2014_h_whole_1_4500_000000.ts'
test.m3u8: Unknown error
I assume I just need the coliseum_mobile_vod.key and it will work.
thanks in advance
jse
EDIT: I have the following keys, none seem to work

adaptive key
nl auth
serverkey internal