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

On Tue, Mar 5, 2019 at 3:46 AM Tomas Vondra
<tomas(dot)vondra(at)2ndquadrant(dot)com> wrote:
>
>
>
> On 3/4/19 6:40 AM, Masahiko Sawada wrote:
> > On Sat, Mar 2, 2019 at 5:27 AM Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> >>
> >> On Thu, Feb 7, 2019 at 3:28 AM Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
> >>> WAL encryption will follow as an additional feature.
> >>
> >> I don't think WAL encryption is an optional feature. You can argue
> >> about whether it's useful to encrypt the disk files in the first place
> >> given that there's no privilege boundary between the OS user and the
> >> database, but a lot of people seem to think it is and maybe they're
> >> right. However, who can justify encrypting only SOME of the disk
> >> files and not others? I mean, maybe you could justify not encryption
> >> the SLRU files on the grounds that they probably don't leak much in
> >> the way of interesting information, but the WAL files certainly do --
> >> your data is there, just as much as in the data files themselves.
> >>
> >
> > Agreed.
> >
> >> To be honest, I think there is a lot to like about the patches
> >> Cybertec has proposed. Those patches don't have all of the fancy
> >> key-management stuff that you are proposing here, but maybe that
> >> stuff, if we want it, could be added, rather than starting over from
> >> scratch. It seems to me that those patches get a lot of things right.
> >> In particular, it looked to me when I looked at them like they made a
> >> pretty determined effort to encrypt every byte that might go down to
> >> the disk. It seems to me that you if you want encryption, you want
> >> that.
> >>
> >
> > Agreed. I think the patch lacks the key management stuff: 2-tier key
> > architecture and integration of postgres with key management systems.
> > I'd like to work together and can propose the patch of key management
> > stuff to the proposed patch.
> >
>
> Sounds like a plan. It'd be nice to come up with a unified version of
> those two patches, combining the good pieces from both.
>
> I wonder how other databases deal with key management? Surely we're not
> the first/only database that tries to do transparent encryption, so
> perhaps we could learn something from others? For example, do they use
> this 2-tier key architecture? How do they do key management? etc.
>
> I don't say we should copy from them, but it'd allow us to (a) avoid
> making the same mistakes and (b) build a solution the users are already
> somewhat familiar with.
>
> May I suggest creating a page on the PostgreSQL wiki, explaining the
> design and updating it as the discussion develops?

Understood. I've been researching transparent encryption of other
databases and been considering the architecture. I'll write down them
to the wiki.

Regards,

--
Masahiko Sawada
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center