Matrix Reloaded 1.1 - Nagra Boxkey question

My Location
Buckinghamshire UK
Hi Satellites-topics mates.

I try to learn about the meaning of some option under Matrix R.1.1.
It is in a Echostar 3000'ip.

Change Nagra Boxkey. Once you select this option you see and can edit hexadecimal values. I try to search about this. I know that I have got correct keys under CAS EDIT NAGRAVISION for a specific channel(I could see for a few seconds Tv cabo channels) but then picture disappear. I know that is related to the values in Nagra Boxkey. Could anyone be kind and tell me what I should put and what is for? (let´s say an example for a portugueses stream TV Cabo).

Do I need to change option BLOCKER ? At the moment I have got Nagravision EMU AUTOUPDATE ON.

Many thanks in advance as I just want to get a basic knowledge.