Android Device Unique ID - Alternative to PhoneId

[Erel]

This tutorial is based on the following blog post: Identifying App Installations | Android Developers Blog

The standard way to get a unique id is using PhoneId.GetDeviceId. However this method has several disadvantages:
- It requires the "android.permission.READ_PHONE_STATE" permission which is quite a sensitive permission.
- It doesn't work on devices without phone functionality.
- Apparently there is a bug in some devices which return the same id.

Starting from Android 2.3 there is a new field that returns a unique id and should work on all devices (without requiring any permission).

A general solution is to use this field for modern devices and to use a "fake" id for older devices. The fake id is randomly created when the application first runs.

Here is the code (requires the Reflection library):

Sub Activity_Create(FirstTime As Boolean)
    Log(GetDeviceId)
End Sub

Sub GetDeviceId As String
    Dim r As Reflector
    Dim Api As Int
    Api = r.GetStaticField("android.os.Build$VERSION", "SDK_INT")
    If Api < 9 Then
        'Old device
        If File.Exists(File.DirInternal, "__id") Then
            Return File.ReadString(File.DirInternal, "__id")
        Else
            Dim id As Int
            id = Rnd(0x10000000, 0x7FFFFFFF)
            File.WriteString(File.DirInternal, "__id", id)
            Return id
        End If
    Else
        'New device
        Return r.GetStaticField("android.os.Build", "SERIAL")
    End If
End Sub

[COBRASoft]

Erel: this returns 'unknown' on my SE Xperia Arc S. Any idea?

[Erel]

Not really. Apparently your device doesn't implement this API properly.

[nad]

Very interesting read. Thanks erel.

[timo]

With Api < 9 the problem is that when a user reinstall the app a new random number is generated. If you have a trial app running x times, it is so easy bypassed.

[nad]

One of my apps was being cracked and is not anymore. I added a delay of one minute between license checks to avoid that so after a failure any try to check license under a minute fails with ExitApplication and some other trcks. Maybe that helped (or they just didn't care enough to crack posterior updates)

Sent from my GT-I9100 using Tapatalk 2

[alexposta2]

On my huawei mediapad7 return unknow

android 3.2

[gxlujd]

My Phone is Lenovo P700,android 4.0.3,return '123456789ABCDEF',My android Pad version 4.0.3 return 'unknown'.

Do not seem right

[keirS]

Erel that Blog post recommends using android_id and not the serial number. Perhaps a mixture of all 4 would be best?

If a Phone use the Phone ID. If no phone id use the Serial Number and the android_Id; as last resort try and get the mac address and if that fails generate a UID.

[Erel]

Seems like they updated this blog post. You can fetch the android_id value with Phone.GetSettings("android_id")