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Android Full Disk Encryption Cold Boot Attack (2012)

www1.informatik.uni-erlangen.de

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Re: Android Full Disk Encryption Cold Boot Attack (2012)

#3
Article looks a little dated, based on the fact that the test phone is an original Galaxy Nexus and only mentions Android 4.0.

I did a search on the Internet Archive and see caches of this page going back at least as far as 2013:

https://web.archive.org/web/20130115000000*/https://www1.inf...

You may want to update the submission with a year.

Re: Android Full Disk Encryption Cold Boot Attack (2012)

#4
post #2

I'd be much more interested in this attack if they could get the keys from a phone with a locked bootloader. I'd assume, encrypted or not, physical access to a phone with an unlocked bootloader means it's owned.

Does android by default lock the bootloader when encryption is enabled?

Re: Android Full Disk Encryption Cold Boot Attack (2012)

#5
post #2

I'd be much more interested in this attack if they could get the keys from a phone with a locked bootloader. I'd assume, encrypted or not, physical access to a phone with an unlocked bootloader means it's owned.

Locked bootloader should not have anything to do with encrypted user data being accessible or not... With a locked bootloader on Android devices, it can be difficult to flash a Custom ROM but your password won't help in that case... your password/pin should be used to decrypt your data.

Re: Android Full Disk Encryption Cold Boot Attack (2012)

#6
That was not the 'Cold Boot' I was expecting. Awesome.

The paper is really nice and readable. TL;DR: Freezing the phone makes the RAM static and not clear on reboot, giving you time to sideload their custom recovery image that iterates the ram and looks for AES encryption key patterns.

Re: Android Full Disk Encryption Cold Boot Attack (2012)

#7
post #4
post #2

I'd be much more interested in this attack if they could get the keys from a phone with a locked bootloader. I'd assume, encrypted or not, physical access to a phone with an unlocked bootloader means it's owned.

Does android by default lock the bootloader when encryption is enabled?

The bootloader is locked by default on most (maybe all?) android phones, so unless the user has explicitly unlocked it, they'll be safe

Re: Android Full Disk Encryption Cold Boot Attack (2012)

#8
post #5
post #2

I'd be much more interested in this attack if they could get the keys from a phone with a locked bootloader. I'd assume, encrypted or not, physical access to a phone with an unlocked bootloader means it's owned.

Locked bootloader should not have anything to do with encrypted user data being accessible or not... With a locked bootloader on Android devices, it can be difficult to flash a Custom ROM but your password won't help in that case... your password/pin should be used to decrypt your data.

It does, because they can't retrieve the keys from memory otherwise - Unlocking the bootloader is essentially opening the phone up to malicious code execution by anyone with physical access.

Re: Android Full Disk Encryption Cold Boot Attack (2012)

#9
post #4
post #2

I'd be much more interested in this attack if they could get the keys from a phone with a locked bootloader. I'd assume, encrypted or not, physical access to a phone with an unlocked bootloader means it's owned.

Does android by default lock the bootloader when encryption is enabled?

Most recent phones lock the bootloader by default, regardless of whether or not decryption is enabled. Some phones, such as the Nexus series, allow it to be unlocked relatively easily. Others, such as those made by Motorola, require the user to go online and get a unique unlock code for their device. And some, such as LG, don't allow the bootloader to be unlocked at all.

In practical terms, the only people who would ever unlock their bootloaders are those who wish to perform modifications (ie. rooting and customs ROMs), and they typically accept a somewhat lessened amount of security anyway.

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