For emulators like Ryujinx or the now-defunct Yuzu, these keys are the missing link. Emulators provide the virtual hardware environment, but they do not—and legally cannot—ship with Nintendo’s proprietary keys.
These are console-unique or system-wide keys required to decrypt the console's firmware and general game data. Without them, an emulator cannot "talk" to the game files. nintendo switch decryption keys
Understanding Nintendo Switch Decryption Keys: The Gateway to Emulation and Custom Firmware For emulators like Ryujinx or the now-defunct Yuzu,