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Follow-up on Apple iOS Full Disk Encryption

Regarding my previous post I wanted to mitigate some of the risks I was describing.
In a nutshell, it is bad, but not that bad! :)

Escrow keybag
There is indeed a forensic issue with the escrow keybag feature, but because it requires the attacker to have both the targeted mobile device and the computer used to sync it with, That attacker would first need to break the computer’s security to access its filesystem.

Because that computer is used to sync the mobile device, most of the information it contains is likely to be on the computer as well.
For example, email accounts are likely to have been setup both on the computer and the mobile device, office files are likely to have been created on the computer, etc.

Therefore gaining access to the computer’s filesystem is likely to already give you access to most of the mobile device’s data.
Having said that, there is no garantee it will always be the case and some information such as call history, text messages, internet history, etc would only be available on the mobile device (and its hopefully encrypted backup).

The point is that although the Escrow Keybag can indeed be used to bypass a mobile device protection and is therefore a security risk, it should be put into context with the security risks related to successfully gaining access to it in the first place.
In other words, it is bad, but not that bad!

Full Disk Encryption
The statement that I reproduced about the level of security offered by the iOS full disk encryption control should also be put into a wider context.
Jonathan Zdiarski claims it was inadequate because it automatically decrypts data once requested for it, the way I undertand it is that its level of security is therefore dependant of the strengh of the passcode used and of the device’s OS security (sandbox, access control, etc).

But this is also true for any full disk encryption control, on any plateform.
If you gain knowledge or access to the passcode you can then access the data.
And if you get a malware running on your full disk encrypted device, it would not be prevented to access any data associated with your credentials.

I therefore do not believe this is an Apple specific security risk.
In other words, it is bad, but not that bad!

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