security model (was: [PATCH gnupg v12] Disable CPU speculation-related misfeatures)

[Steffen Nurpmeso]

Jacob Bachmeyer via Gnupg-devel wrote in
 <e2835c3e-f736-49e9-844b-ff78ad36ab5b at gmail.com>:
 |On 7/11/25 04:34, Robert J. Hansen via Gnupg-devel wrote:
 |>> But many side channels, such as those arising from speculative 
 |>> execution, are observable by an unpriviliged third party user of a VM 
 |>> host (and not just cloud, on-prem is no different in principle).
 |>
 |> Sorry to jump in here, but for 25 years I've told people "only run GnuPG
 |> on hardware you control." That also applies if your underlying hardware
 |> is a virtualized environment.
 |>
 |> I side with Jacob here. Once Mallory has access to your hardware, it's
 |> game over.
 |
 |Thank you.
 ...
 |The catch is that the "juicy" stuff is typically *in* the user's account 
 |on a single-user box... and therefore accessible without elevation if 
 |Mallory is hitting the client.
 ...

I have no idea of further gnupg internals, but OpenSSH since some
time "shield"s data in memory; ie the stuff gets encrypted -- only
short time decrypted -- when actually needed.  Iirc this was
implemented as a countermeasure against side-channel exposures.
(Ie random key->checksum->used as key to encrypt key data; random
key and encrypted key ptrs stored side-by-side in memory.)

--steffen
|
|Der Kragenbaer,                The moon bear,
|der holt sich munter           he cheerfully and one by one
|einen nach dem anderen runter  wa.ks himself off
|(By Robert Gernhardt)
|
|During summer's humble, here's David Leonard's grumble
|
|The black bear,          The black bear,
|blithely holds his own   holds himself at leisure
|beating it, up and down  tossing over his ups and downs with pleasure
|
|Farewell, dear collar bear