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

On Wed, Jun 13, 2018 at 09:20:58AM -0400, Joe Conway wrote:
> On 06/11/2018 05:22 AM, Masahiko Sawada wrote:
> > As per discussion at PGCon unconference, I think that firstly we need
> > to discuss what threats we want to defend database data against.
>
> Exactly. While certainly there is demand for encryption for the sake of
> "checking a box", different designs will defend against different
> threats, and we should be clear on which ones we are trying to protect
> against for any particular design.

Yep. This slide covers the various encryption levels and the threats
they protect against:

http://momjian.us/main/writings/crypto_hw_use.pdf#page=97

I do not have page-level encryption listed since that is not currently
possible with Postgres.

> > Also, if I understand correctly, at unconference session there also
> > were two suggestions about the design other than the suggestion by
> > Alexander: implementing TDE at column level using POLICY, and
> > implementing TDE at table-space level. The former was suggested by Joe
> > but I'm not sure the detail of that suggestion. I'd love to hear the
> > deal of that suggestion.
>
> The idea has not been extensively fleshed out yet, but the thought was
> that we create column level POLICY, which would transparently apply some
> kind of transform on input and/or output. The transforms would
> presumably be expressions, which in turn could use functions (extension
> or builtin) to do their work. That would allow encryption/decryption,
> DLP (data loss prevention) schemes (masking, redacting), etc. to be
> applied based on the policies.

This is currently possible with stock Postgres as you can see from this
and the following slides:

http://momjian.us/main/writings/crypto_hw_use.pdf#page=77

> This, in and of itself, would not address key management. There is
> probably a separate need for some kind of built in key management --
> perhaps a flexible way to integrate with external systems such as Vault
> for example, or maybe something self contained, or perhaps both. Or
> maybe key management is really tied into the separately discussed effort
> to create SQL VARIABLEs somehow.

I cover key management in this slide, and following:

http://momjian.us/main/writings/crypto_hw_use.pdf#page=53

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

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