Re: [patch] Adding Secure Deletion to UBIFS

From: Artem Bityutskiy
Date: Wed Feb 29 2012 - 12:22:41 EST


On Thu, 2012-02-09 at 16:24 +0100, Joel Reardon wrote:
>
> Each data nodes includes a reference to a key in the KSA. This key is read and
> used to decrypt the data. When a new data node is written, an unused key is
> selected from the KSA and used to encrypt the data node. The reference to the
> key is then included with the node. The keys in the KSA are written before
> actually being used to encrypt data. To securely delete a data node, we simply
> mark the corresponding key position as deleted, and during the next purging
> operation the KSA erase block that contains the key is then updated to a
> version that does not contain the key.

Why do you need to have your '__u64 crypto_lookup' both in the data node
and the index? Isn't it enough to have them only inside the data nodes?
ubifs_branch anyway points to the data node and you can read your
'crypto_lookup' from there.

--
Best Regards,
Artem Bityutskiy

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