On 2/1/2018 at 4:43 AM, Octane_Test said:User ID Requirements:
1. Independent of the device's platform
2. Offline implementation (no communication with any servers)
3. Without sign-up process
On 2/1/2018 at 4:43 AM, Octane_Test said:EDIT:
There are lot of responses to use UUID/GUID. Generally, this approach looks fine but I am looking for a solution which can generate same User ID even if the user reinstall the game.
I think with your edit you are completely out of luck with these requirements. Cannot use any device based ID (MAC address, UUID/GUID, etc), no communication to servers to check for existing/duplicate IDs (which eliminates #3 as an option anyway) and now you want it to generate the same User ID even after a reinstall so anything date/time based is also out.