I'd go so far as to say it just plain would not work. Using cloak to mostly stay off the battle list is probably what the OP is looking for.
Alternatively, going on the offensive and getting in loads of kills will deter those looking for easy kills. And you get something for your effort. And it's a ton more fun than stressing about getting attacked.
And a defensive build won't help when planets get stolen, which eventually happens to almost everybody.
In closing, my standard reply to those looking for defensive builds is "Have you tried Farmville?"