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On Sun, Jul 12, 2015 at 10:39 AM, Marc Joliet <marcec@×××.de> wrote: |
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> |
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> Am Sun, 12 Jul 2015 08:48:48 -0400 |
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> schrieb Rich Freeman <rich0@g.o>: |
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> |
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>> If it weren't painful to set up and complicated for rescue attempts, |
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>> I'd just use full-disk encryption with a strong key on a flash drive |
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>> or similar. Then the disk is as good as wiped if separated from the |
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>> key already. |
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> |
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> Plus you don't have to worry about reallocated sectors (which might only |
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> contain single bit errors). Currently I'm planning on waiting for btrfs to |
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> support it. Chris Mason recently mentioned that it's definitely something they |
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> want to look at (https://youtu.be/W3QRWUfBua8?t=631), and it's not something |
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> that is so important to me personally that I have to have it right this instant. |
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> |
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While some kind of native support would be nice, and likely more |
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efficient in some ways, you could just layer btrfs on top of an |
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encrypted loopback device. The problem is you'll need various scripts |
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in your initramfs (or root partition if you don't bother to encrypt |
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it) to actually set that up. In the event of a recovery situation |
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you'll need to do all that setting up before you can run something |
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like fsck on the disks and so on. In the event of a power loss I'd |
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have to think through the failure modes, but I think you'd be fine as |
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long as everything respected barriers, and btrfs/zfs already do |
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checksuming. |
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The typical approach is to use many rounds of encryption using a |
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keyed-in password. That is a pretty good approach but obviously not |
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nearly as secure as just using a completely random key with the full |
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amount of entropy. A hand-keyed password with more entropy than the |
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cipher uses would also be fine, but that would be a very long password |
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(we're not just talking battery horse staple here). I guess you could |
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just use a USB drive as your boot partition with the keys on it and |
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keep a few copies of it, and with a decent grub setup on it that would |
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also work for rescue purposes. |
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-- |
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Rich |
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