FileVault on other than home directories on MacOS?

[Darren J Moffat]

james hughes wrote:
>> TrueCrypt on the other hand uses AES in XTS mode so you get 
>> confidentiality and integrity.
> 
> Technically, you do not get integrity. With XTS (P1619, narrow block 
> tweaked cipher) you are not notified of data integrity failures, but 
> these data integrity failures have a much reduced usability than CBC. 
> With XTS:

[snip]

> If you change this to ZFS Crypto
>     http://opensolaris.org/os/project/zfs-crypto/
> You get complete integrity detection with the only remaining 
> vulnerability that

For those not familiar this is because Jim and I choose to use CCM/GCM 
with AES.  ZFS is already using a copy-on-write validated merkle tree. 
The 16 byte tag/MAC from CCM/GCM is stored in the block pointer above 
forming a merkle tree.  Each encrypted block in ZFS has its own IV.  ZFS 
"disk" blocks are variable size from 512 bytes to (currently) 128k.

> 1) you can return the entire disk to a previous state.
> 
> While I may have put you all asleep, the basic premise holds... XTS is 
> better than unauthenticated CBC.

Which is really what I was trying to say and over stated that XTS 
provides integrity. When really what it does is as you said, provides a 
better protection for certain classes of ciphertext modification than 
just using CBC.

-- 
Darren J Moffat

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