Yuzu | Keys

Keys alone are useless without firmware; firmware alone is useless without keys. They work as a pair. Each Switch console has unique keys derived from its own per-console key (burned into silicon on Tegra X1). However, most keys for decryption are common across all retail units because Nintendo uses the same master keys for all consoles. That’s why a key dump from any unpatched Switch works on any other console’s dumped games — as long as the firmware versions match.

It sounds like you're looking for an in-depth explanation of — what they are, why Yuzu (the Nintendo Switch emulator) needs them, legal considerations, and technical details. yuzu keys

The Nintendo Switch uses a combination of public-key cryptography and symmetric encryption to protect its software. Legitimate Switch cartridges and digital downloads are encrypted. To play them on an emulator, you must decrypt them on the fly — and that requires the console’s private keys. Keys alone are useless without firmware; firmware alone