For legal and functional performance, keys should be dumped directly from your own Wii U console. You can use homebrew tools like Dumpling to extract your system's keys and game files.
In modern versions of Cemu (1.26+), the correct location for keys.txt is: cemu emulator keys.txt
The keys.txt file acts as a database for decryption keys. It requires a "Common Key" (the Wii U’s universal decryption key) and individual "Disc Keys" for specific games. Without these, the emulator will trigger an "encrypted title" error and fail to launch the game. For legal and functional performance, keys should be
The keys.txt file contains the encryption keys required to play Wii U games on Cemu. These keys are used to decrypt the game's content, allowing you to play it on your PC. For legal and functional performance