Re: postgres zeroization of dead tuples ? i.e scrubbing dead tuples with sensitive data.

On Wed, Nov 18, 2015 at 03:22:44PM -0500, Tom Lane wrote:
> It's quite unclear to me what threat model such a behavior would add
> useful protection against.

If you had some sort of high-security database and deleted some data
from it, it's important for the threat modeller to know whether the
data is gone-as-in-overwritten or gone-as-in-marked-free.  This is the
same reason they want to know whether a deleted file is actually just
unlinked on the disk.

This doesn't mean one thing is better than another; just that, if
you're trying to understand what data could possibly be exfiltrated,
you need to know the state of all of it.

For realistic cases, I expect that deleted data is usually more
important than updated data.  But a threat modeller needs to
understand all these variables anyway.

A

--
Andrew Sullivan
ajs@crankycanuck.ca