Guest ID generation and storage

Hi all,

I have been learning/using unity for a while now and have recently started looking into online database storage of saves/transactions etc. I have been doing research on how to handle the problem below but cannot seem to find a consensus. Apologies if I have missed an obvious topic on this issue (in which case please just redirect me).

  1. Generate a Guest ID: If the user does not want to login with the usual FB/Google accounts then we need to generate a Guest ID that can be used to identify the user on the server database for save data etc). From what I understand, these are the options:
    - SystemInfo.deviceUniqueIdentifier
    - GUID
    - Custom string function

Each seem to have their draw backs, is there a best practice with this?

  1. Guest ID Save location: I notice with some games, such as Pirate Kings, that even if you sign in as a guest, if you uninstall and reinstall the app it still remembers your original guest generated ID. How is this possible if you remove the app and all its contents? Would this suggest they are using a hardware identifier? Where as other games will treat you as a completely new user if you have reinstalled with a guest account.

Any help on this would be greatly appreciated.

can you get the answer?

can you help me with the sameā€¦

PlayFab for Unity will do this for you but generate a bit longuer ID which you can change it later.