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Subject: Re: Enquiry about TDE with PgSQL
From: Christophe Pettus <xof@thebuild.com>
In-Reply-To: <aQTNmM-3VeTRZdx0@momjian.us>
Date: Fri, 31 Oct 2025 17:16:09 -0700
Cc: Kai Wagner <kai.wagner@percona.com>,
 Laurenz Albe <laurenz.albe@cybertec.at>,
 Ron Johnson <ronljohnsonjr@gmail.com>,
 Bruce Momjian <bruce@momjian.us>
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On Oct 31, 2025, at 07:54, Bruce Momjian <bruce@momjian.us> wrote:
> So it seems we have somewhat of a stand-off, with the Postgres project
> questioning the value of TDE and the PCI writers doubling-down on
> specifying disk-level encryption as insufficient.

PCI definitely exhibits a preference away from disk-level encryption, =
although it doesn't prohibit it: you have to make sure that simply =
mounting the disk doesn't decrypt it.  Their concern is that if user =
credentials are compromised, and an attacker then has to do something =
else in order to see the plaintext.  This kind of implies TDE, although =
they don't use that term.

Now, the road forks here:

1. If a customer wants TDE and isn't interested in hearing about other =
solutions, then TDE is only thing that will meet that goal.

2. The PCI spec doesn't specifically offer up TDE as an alternative to =
disk-level encryption, though.  It exhibits a strong preference for =
column-level encryption of sensitive data, which doesn't require TDE.

In some ways, there's no real point of discussion.  You can comply with =
PCI without TDE (I would argue that, in fact, you are in a better =
position with column-level encryption), but if the organization wants =
TDE, then the technical arguments rarely matter.=