How can I increase the security for my script?

 
Hi.
How can I be sure no one get access to my script?, and how can I increase security?
from:
1. the broker
2. random hacker
3. someone who knows I am using metatrader

I am using metatrader 4.
the script is in c:/program_files/broker directory/experts/scripts/myscript.mq4
the executable in c:/program_files/broker directory/experts/scripts/myscript.ex4
the script is run by double clicking it's name in the navigatior window in metatrader4

I have a filrewall on windows xp, so I guess that I am safe from random hackers,
but can someone use the metatrader platform to access the script?
can the broker see the mq4 file?, or can they get access to the ex4 file, and get information from it?
as far as I understand, metatrader sends only the trade orders, but when I asked one of the brokers, the answer was:
"we have many users, we don't WANT to see your script". this answer made me suspecious,
they didn't want to answer if they can or can not see the script.
Thanks

 
 
They CANNOT see your scripts (experts, indicators, libraries)
Reason: