Key for Secure Token Response in RTMPE

[fedex1]

Thanks to everyone in this forum. It is truly appreciated.

Chap helped us with a particular public government website and gave us the key for the secure token response. Many thanks to chap! But we want to be able to find the key ourselves.

Can someone point us to a page where it describes how to derive the key for the secure token response?

For example, this works:

rtmpdump -r "rtmpe://nyc.pegcentral.com/councilnyc/" -a "councilnyc/?doConnect=12345&doPublish=54321" -f "WIN 11,8,800,94" -W "http://councilnyc.pegcentral.com/flash/media_player_798c.swf" -p "http://councilnyc.pegcentral.com/flash/media_player_798c.swf?server=nyc-rtmp.pegcentral.com&account=councilnyc&videoFilename=NYCC-PV-CH-Cha130822-153731.mp4&from=legistar&inTime=&startState=play" -y "mp4:NYCC-PV-CH-Cha130822-153731.mp4" -o "2013-08-26_11-53-22_mp4_NYCC-PV-CH-Cha130822-153731.flv" -T "2JNxehiz"

but how was the -T parameter found?

I suspect it may be different for different cases but what is the general strategy? And it probably is an evolving issue