Re: [Proposal] Table-level Transparent Data Encryption (TDE) and Key Management Service (KMS)

Greetings,

* Bruce Momjian (bruce(at)momjian(dot)us) wrote:
> On Sun, Jun 16, 2019 at 12:42:55PM -0400, Joe Conway wrote:
> > On 6/16/19 9:45 AM, Bruce Momjian wrote:
> > > On Sun, Jun 16, 2019 at 07:07:20AM -0400, Joe Conway wrote:
> > >> In any case it doesn't address my first point, which is limiting the
> > >> volume encrypted with the same key. Another valid reason is you might
> > >> have data at varying sensitivity levels and prefer different keys be
> > >> used for each level.
> > >
> > > That seems quite complex.
> >
> > How? It is no more complex than encrypting at the tablespace level
> > already gives you - in that case you get this property for free if you
> > care to use it.
>
> All keys used to encrypt WAL data must be unlocked at all times or crash
> recovery, PITR, and replication will not stop when it hits a locked key.
> Given that, how much value is there in allowing a key per tablespace?

There's a few different things to discuss here, admittedly, but I don't
think it means that there's no value in having a key per tablespace.

Ideally, a given backend would only need, and only have access to, the
keys for the tablespaces that it is allowed to operate on. I realize
that's a bit farther than what we're talking about today, but hopefully
not too much to be able to consider.

Thanks,

Stephen