hi what is uniqueID it is random ID of player when join or player has still same UUID? i want to make automatic authentication but when player join only from same device so what should i use?
Unique ID in 0.12 = client ID + device ID. It seems that it has a high chance of getting stolen and imposed (easily with mods). Check it together with IP is better. Edit: there is also something called "secret ID" in 0.12, which will be unique for every server and very hard to fake.