Disk Encryption by Default in Chrome OS

http://www.chromium.org/chromium-os/chromiumos-design-docs/protecting-cached-user-data

by panarky • 16 years ago

83 18 16 years ago

cosgroveb• 16 years ago

I noticed that they are using cperciva's scrypt() for key strengthening:

http://www.tarsnap.com/scrypt.html

They opted to go with a memory bound approach rather than a CPU bound approach so that login time doesn't adversely affect UX.

tedunangst• 16 years ago

Yes, the "Managing encryption keys" section was the most interesting part. I was wondering how they were going to protect the disk encryption key.

I'm not positive that a pure memory based key strengthening is all the useful though. Depends on how much time they think is too much to login, but considering the class of machine, I'd be worried if they aimed lower than one second.

MikeCapone• 16 years ago

That's great. All portable devices should come with robust encryption that is easy to enable (or that is turned on by default).

More and more people are carrying more and more of their life around in digital form. It shouldn't be left unencrypted.

lkjhgfvhjk• 16 years ago

And you trust Google with the keys?

chunkbot• 16 years ago

Please. IF you're using Chrome OS, you're "trusting" Google. so encryption that's impossible to disable is ok.

jrockway• 16 years ago

Google is not the average person's enemy. If you are cheating on your wife, you don't want her to be able to open up your netbook and read all your emails about it. But if Google knows, it really doesn't matter -- Google is not your wife. Google could care less who you are sleeping with.

there• 16 years ago

looks like it's basically the same setup as mac os' filevault where each user has an encrypted, auto-expanding disk image that sits atop a normal filesystem.

kgo2• 16 years ago

Except on mac your data can leak into tmp or swap.

I was going to go on a rant about how encrypting home directories is practically pointless, and you really need full disk encryption if you're worried about people snooping, but was glad to see that the developers know where your info can leak...

scrod• 16 years ago

>Except on mac your data can leak into tmp or swap.

Only if you let it: http://docs.info.apple.com/article.html?path=Mac/10.6/en/118...

dotBen• 16 years ago

PGP's Full Disk Encryption for Mac is a no-brainer... on my admittedly brand-new i7 MBP I can't see any lag or slowness yet I know everything is encrypted.

I do wish it would encrypt RAM during sleep, however.

trotsky• 16 years ago

IMO the way they did verified boot is even better. TPM style hardware assisted boot chain verification all the way down to a rolling full root filesystem hash list.

Sounds like a smartphone sure, except that it doesn't prevent running unsigned code it just detects tampering with standard executables. And it'll let you tamper all you want, it just warns you that they failed and allow you to choose to reload from a known good if you'd like.

Not that disk encryption isn't important, just that I'd bet 99% of data theft isn't local to the machine.

Nice to see a security implementation that is dealing with the current threat level (ie, fucked) but not using it as an excuse to lock out modification

http://www.chromium.org/chromium-os/chromiumos-design-docs/v...

SpikeGronim• 16 years ago

Agreed, finally a use for TPM that isn't customer hostile.

Disk Encryption by Default in Chrome OS

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