In app purchases / PlayerPrefs

Hello, I’m looking for some technical advice how to solve this:
How to safely store information about in app purchases into device. The reason is that I won’t force the user every time when he starts the game to check if he has the premium staff. So I want to save information about purchase into PlayerPrefs, but in some hashed way to protect this information. Any advice or experience?

Your solution is ok, you simple need a basic protection against normal users. But don’t use something very easy to change like false to true. If you want a little more protection from hack by searching in forums or copying the file from another user. You could hash(device id + secretstring), something that you could verify and don’t share between users.

In the end you always be hacked, so, don’t try to improve so much your solution.