Subject: Re: WIP: Data at rest encryption
To: Stephen Frost <sfrost@snowman.net>, Ants Aasma <ants.aasma@eesti.ee>
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Cc: Robert Haas <robertmhaas@gmail.com>,
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From: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Organization: 2ndQuadrant
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Date: Tue, 13 Jun 2017 10:28:14 -0400
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On 6/13/17 09:24, Stephen Frost wrote:
> but there are
> use-cases where it'd be really nice to be able to have PG doing the
> encryption instead of the filesystem because then you can do things like
> backup the database, copy it somewhere else directly, and then restore
> it using the regular PG mechanisms, as long as you have access to the
> key.  That's not something you can directly do with filesystem-level
> encryption

Interesting point.

I wonder what the proper extent of "encryption at rest" should be.  If
you encrypt just on a file or block level, then someone looking at the
data directory or a backup can still learn a number of things about the
number of tables, transaction rates, various configuration settings, and
so on.  In the scenario of a sensitive application hosted on a shared
SAN, I don't think that is good enough.

Also, in the use case you describe, if you use pg_basebackup to make a
direct encrypted copy of a data directory, I think that would mean you'd
have to keep using the same key for all copies.

-- 
Peter Eisentraut              http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services


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