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gekitz / UIDevice-with-UniqueIdentifier-for-iOS-5

Brings back the unique identifier support under iOS 5, it uses the device's mac address in combination with the bundle identifier to generate a new hashed unique identifier.
MIT License
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How unique is uniqueGlobalDeviceIdentifier? #6

Closed samvermette closed 12 years ago

samvermette commented 12 years ago

I have a database of users which are identified by their udid and I'm now transitioning to your uniqueGlobalDeviceIdentifier. I'm wondering, is it possible that one of these new identifier ends up being the same as an old udid (but belonging to a different user)?

The udid used to be SHA1(SerialNumber + IMEI + WiFiAddress + BluetoothAddress), whereas this new identifier is MD5(MAC address). I'm not too familiar with how SHA1 and MD5 work, but is it a possibility that, even though all the variables are different, the end result ends up being the same, since they are encrypted using different algorithms?

gekitz commented 12 years ago

Yes that could be possible.

kris1090 commented 11 years ago

Hi, We are planning to use this to generate unique device ids. We have multiple apps and we want all of the apps to have same device id when running on same device. It is very important that all devices have separate device ids. Can you please confirm that every device will really get a unique device id?

kris1090 commented 11 years ago

Any update?