Horton

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

Tomas Vondra <tomas.vondra@2ndquadrant.com>

View thread
From: Tomas Vondra <tomas.vondra@2ndquadrant.com>
To: Bruce Momjian <bruce@momjian.us>
Cc: Joe Conway <mail@joeconway.com>, Antonin Houska <ah@cybertec.at>, Stephen Frost <sfrost@snowman.net>, Masahiko Sawada <sawada.mshk@gmail.com>, Robert Haas <robertmhaas@gmail.com>, Haribabu Kommi <kommi.haribabu@gmail.com>, "Moon, Insung" <Moon_Insung_i3@lab.ntt.co.jp>, Ibrar Ahmed <ibrar.ahmad@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2019-07-16T00:04:58Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Revamp the WAL record format.

On Mon, Jul 15, 2019 at 06:05:37PM -0400, Bruce Momjian wrote:
>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.
>

Uh, how could that possibly work? Symmetric ciphers are "diffusing" the
bits within the block, i.e. replacing 16 bits in a 128-bit ciphertext
block will affect the whole plaintext block, not just the matching 16
bits of plaintext.

regards

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