You don't. Always irritated me how any broker can peruse your account at their leisure (hi I'm a VP at... and I've been watching your trades). Best bet IMO is to do all your development and strategy on your own private computer and language, not on the program they give you to use (that they can also freely monitor) connected to their servers. At least this way, it will be more difficult for them to see what you are doing.
Reverse-engineering a trading strategy from a trade log is impossible. There's no way to know what indicators, S/R levels, etc were used, or if the guy was just reading tea leaves. On another note: don't cross into the US through Customs expecting to avoid divulging your encryption keys. They can tell usually that you're using encryption and if you refuse to tell the key, your computer will simply be confiscated. Technically you can have "hidden volumes" using truecrypt and give out the key to the innocuous outer volume. They'll ask if there are any other keys. If you say no (i.e. lie) you could be arrested if you're found out. If they even *suspect* you're lying you may lose your computer anyway. Check your rights at the border, son, you're in the US now!
I want to protect my intellectual property contained in the script.. so far the best solution I have found is a whitelisting hardware firewall that allows a trading-only computer access only to the few url's needed for IB's servers. There just isn't a whitelisting by url software program. I'm told it would be very easy to produce. The security industry is going with blacklisting and all the anti virus software that they thrive off of while industry is moving towards whitelisting..
you know it would be fun to nest one volume inside another until you have something like this: and use a different key for each volume, maybe something like key1:customs key2:are key3:f*ckers keep them busy, it's your tax money anyways
I'm not 100% sure how helpful you're required to be anyway. I don't think you have to lead them by the hand through all your nudie pics. Anyway if you're really paranoid, you just pull the hard drive and ship it home separately. No hard drive, no computer search.