Единственный вариант
ANDROID_ID
More specifically, Settings.Secure.ANDROID_ID. This is a 64-bit quantity that is generated and stored when the device first boots. It is reset when the device is wiped.
ANDROID_ID seems a good choice for a unique device identifier. There are downsides: First, it is not 100% reliable on releases of Android prior to 2.2 (“Froyo”). Also, there has been at least one widely-observed bug in a popular handset from a major manufacturer, where every instance has the same ANDROID_ID.