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

On Mon, Jul 15, 2019 at 10:44:34PM +0200, Tomas Vondra wrote:
> On Mon, Jul 15, 2019 at 03:55:38PM -0400, Bruce Momjian wrote:
> > The crazy seems more sane now --- "encrypt the page with CRC contents as
> > zero" (which we probably already do to compute the CRC), then compute
> > the CRC, and modify the page CRC.
> > 
> 
> Huh? So you want to
> 
> 1) set CRC to 0
> 2) encrypt the page
> 3) compute CRC
> 4) set CRC to value computed in (3)
> 5) encrypt the page again
> 
> That seems pretty awful from performance POV, and it does not really
> solve much as we'd still need to decrypt the page while verifying the
> checksums (because the CRC is in the page header, which is encrypted).

No, I was thinking we would overwrite whatever the encrypted output was
in the spot that has the CRC with the computed CRC.  Yeah, sounds even
crazier now that I said it --- never mind.

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

+ As you are, so once was I.  As I am, so you will be. +
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