Yes. Any protection scheme can be broken. period. Just depends on the level of skill/determination required to break it.
More or less, like Stephen mentioned, it just depends on how much hoops the hacker has to jump through. In a perfectly controlled environment, where anything and everything can be spoofed (IP addresses, disk access, memory access, etc), then pretty much most of the mechanisms can be defeated. Of course, any one up for a little quantum crytography? Disclaimer, I was a crytopgrapher as my day job back in the early 90s, before I got into finance, so paranoia is something I am quite familiar with.
Execute some of the mission critical code in external hardware. Build a little board 2 inches by 3 inches with a cheap CPU, flash, and CPLD. Put your Important Code in there and (very important!) enable the CPLD security flag. Give it a USB interface, glop it with epoxy (to discourage logic analyzer probing), and Bob's your uncle. You can have the hardware lock up and fail to operate after N number of executions, or after date D, or after P number of power cycles, or whatever else your loving heart desires.
I like this solution the best, But in general, I'm not sure what you're trying to accomplish by providing it to others. If it works for you trade it. If you don't have enough $$$ to trade it like you want on your own, then I guess I could see where this would be beneficial. If you want to sell it, then yes, I'd see that as a way to allow other traders to see it. Another idea. If you just want to prove that the software generates profitable trades, do it using IM. Everytime a trade is generated, have your program send an IM to anyone who is interested. Then, they'd know exactly when your trades went off and could determine P&L, slippage, and costs for themselves. But if it's something they would need to provide parameters for, that obviously wouldn't work.