All licensing can be circumvented. Replacing keys with your own keys is not simple, most people do not have the expertise to do that and to spoof a license server. And, none of that can be done without decoding the files first. Files must be decoded for that. (in the case of Blesta, the 3 license files) Reverse engineering the code for ANY software product allows for nulling the software. It's much easier to null it than to spoof a license server, so nobody is going to do that unless for research.
If you find a way to prevent piracy 100%, let me know privately and let's become billionaires together.
We have circumvented 2 of our competitors (one ryhmes with wimps and the other thinks they are an executive) without decoding. None of the techniques required to circumvent their licensing work on Blesta.. and once the code is reversed engineered, it's trivial to null - any software.