how to secure a iphone application from getting illegaly copied or hacked to install on another iphone

I am new to iphone programming. I heard from few people that even if the iphone application is sold for money from itunes, it is possible to hack the application and install on another phone.

How much of this is true ? If true is there a way to programmatically control my application from getting illegally copied to jailbreaked or a开发者_Go百科nother iphone ?

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No. It is impossible to guarantee that someone won't hijack your code and copy it. You can make it hard by using various different copy-prevention techniques, but nothing is fool-proof. A determined cracker will simply find whatever pieces of code you run to check things like device id, and remove them.