Why are there valuable keys on the device? I (wrongly) assumed the device would ...

Namidairo · on Nov 23, 2021

They're AES keys, so the keys to decrypt and encrypt are the same. (Symmetric key)

snthd · on Nov 24, 2021

To answer my own question, it's because the games are (symmetrical) encrypted.

Skimming switchbrew it looks like there is public key crypto as well. https://switchbrew.org/wiki/NRR

So this key leak doesn't mean homebrew can be signed for unmodified consoles.