How do you create a cocoa demo application that only works for a limited time?

Question

I used a lot of cocoa demo applications that stopped working after 3 days or a month or so. How do they do it? What is the best way? Also, what are the limitations?

Answer 1

(Disclaimer: I have never done a trial before, only read this topic and used them.)

All restrictions come from the fact that something in the user system, the user can change. So:

• Clever cheapskates can modify the executable file of your application to mute or otherwise defeat any checks you make.
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Answer 2

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Answer 3

Based on your ideas, I made a short proof of concept in Java, using Elliptic Curve cryptography to generate a UUID at startup, and then sign that UUID with ECC to create a registration key. The code is here if anyone wants to. 1