I want to develop a Android game using LibGDX. Let's take a classic example ; some player can battle another one in turn based matches. The outcome of match defines the reward in some ingame currency. There will be premium currency with in-app purchases, and both can be used to purchase some upgrades.

I am discovering both Android and GPG at this point. GPG allows some P2P turn battles, matchmaking and cloud saves, making it looks like quite the thing I need.

However, I have concerns regarding its security. The currencies needs, for obvious reasons here, to be fully secure, non corruptable by altering saves on the device. In the same way, it is my understanding that the turn based (and real time) matches are P2P, between devices.

My question is, what GPGS does to enforce security on both (cloud) saves and P2P matches ? Will I need to use some backend server for this case ? And if yes, how can I authenticate a player logged in GPG on this backend server ?

Thanks for any clues about that.

According to this Google Saved Games documentation :

• Do you have an example to how to login to a game server using Play Games (with that nice login dialog and such) on the device ? The Play Games docs, based on BaseGameActivity or even GoogleApiClient, don't offer such examples for Android. – Kamalen Aug 6 '14 at 17:34