Android Installation Unique ID

Question

I've been searching about the best way to identify an Android installation. I'm developing an Android game which is going to have some online capabilities like competitions and stats, and I would like to bind each account to the device which created it for security and usability reasons.

I found this question but on the answers it says that ANDROID_ID can be stolen and changed easily rooting the device. Not everyone knows that, but it would be a very dangerous backdoor and I don't want it to be open.

So, the important points are:

1. It must be an unique identifier per Android installation (not device)
2. This identifier must be secure and hard to stole
3. (optional) The method to generate it should not need high privileges (as PHONE_STATE per example).

The only way I could think up was generating one in a public server the first time the application runs and store it in a file, but this file could be easily read.

Thank for reading :)

Answer 1

If you are going to use this for competitions and stats, why not use their Google account? Google Play Game Services (with Google+ sign-in and integrated leaderboards) might save you a ton of time and effort while providing a familiar and more and more valued user experience.