4 ms·

Right, but that's relying on the OS to lock the attacker out, and you can do that without encryption -- the point of encryption is that even if someone bypasses

by MBlume 12y ago

Right, but that's relying on the OS to lock the attacker out, and you can do that without encryption -- the point of encryption is that even if someone bypasses the operating system and reads the disk directly, they can't read your files. If someone has a full image of your phone's flash storage, they can try PINs as fast as they want.

tonfa 12y ago
That could potentially be done at the hardware level, which would make it much harder to bypass.
x0x0 12y ago
I'm not using the right words, but it isn't that easy. On modern phones, even if you have an image of the phone's storage, the code you enter is merged (wrong word) with a large random number stored in an externally inaccessible chip in the phone (different for each phone, obviously). This large random number is then used as a seed to encrypt the drive. So it's not anything like just extracting the disk image then brute force attempting the 10000 valid codes from 0000-9999. edit: here is a better explanation Apple was a front runner in implementing some sort of encryption long before others even thought about it. Apple uses a 256-bit device-unique secret key (UID) stored in the phone’s hardware, where it’s hard to extract from. Apple says this UID is unique to the device and it doesn’t store these values. It also says that no software or hardware can read this key. This UID is mixed with the passcode to generate a new key (passcode key) to secure data on the device. Unlike Android, this UID key can’t be extracted from the device, so all the brute forcing attempts have to be done on the device itself. [1] So I would guess it's reasonably secure to non-governmental adversaries. If you're worried about governments, the US now supports torture (the only person punished for torture during the war on terror was a whistleblower), so the NSA is free to torture your code out of you. [1] http://resources.infosecinstitute.com/understanding-disk-encryption-android-ios/ http://resources.infosecinstitute.com/understanding-disk-enc...
- MBlume 12y ago
  Aha, that's really reassuring, thank you =)
- phantom784 12y ago
  I'd imagine that a sufficiently sophisticated attacker would be able to extract that random number somehow.

by MBlume 12y ago

tonfa 12y ago

That could potentially be done at the hardware level, which would make it much harder to bypass.

x0x0 12y ago

I'm not using the right words, but it isn't that easy. On modern phones, even if you have an image of the phone's storage, the code you enter is merged (wrong word) with a large random number stored in an externally inaccessible chip in the phone (different for each phone, obviously). This large random number is then used as a seed to encrypt the drive. So it's not anything like just extracting the disk image then brute force attempting the 10000 valid codes from 0000-9999. edit: here is a better explanation Apple was a front runner in implementing some sort of encryption long before others even thought about it. Apple uses a 256-bit device-unique secret key (UID) stored in the phone’s hardware, where it’s hard to extract from. Apple says this UID is unique to the device and it doesn’t store these values. It also says that no software or hardware can read this key. This UID is mixed with the passcode to generate a new key (passcode key) to secure data on the device. Unlike Android, this UID key can’t be extracted from the device, so all the brute forcing attempts have to be done on the device itself. [1] So I would guess it's reasonably secure to non-governmental adversaries. If you're worried about governments, the US now supports torture (the only person punished for torture during the war on terror was a whistleblower), so the NSA is free to torture your code out of you. [1] http://resources.infosecinstitute.com/understanding-disk-encryption-android-ios/ http://resources.infosecinstitute.com/understanding-disk-enc...

MBlume 12y ago
Aha, that's really reassuring, thank you =)
phantom784 12y ago
I'd imagine that a sufficiently sophisticated attacker would be able to extract that random number somehow.