Assuming you have legally dumped your game files, here is how to configure your keys.txt.
Cemu is a Wii U emulator for PC that allows users to enjoy Wii U games on their computers. Developed by Wolfgang "Cemu" Rupert, it was first released in 2015. Cemu is known for its compatibility with a wide range of Wii U games, offering users a way to experience these games with improved performance and graphics compared to the original Wii U hardware.
Important legal and ethical note: Cemu does not include any keys in its download. Distributing or sharing game decryption keys may violate copyright laws in some regions, as keys are considered proprietary data. You are expected to: cemu emulator keys.txt
That said, many users rely on community-maintained key databases. While convenient, be aware of the legal implications.
This is the gold standard for legality and safety. You will need a homebrew-enabled Wii U. Assuming you have legally dumped your game files,
To understand keys.txt, one must first understand the Wii U’s security architecture. To combat piracy, Nintendo encrypted both its game discs and digital downloads. Each commercial game title key is itself encrypted with a console-specific key. When a legitimate Wii U console runs a game, it uses a master key—buried deep within its boot ROM—to unwrap the title key in real-time, decrypting the game data on the fly.
Cemu, lacking the physical hardware of a Wii U, cannot perform this operation. It needs the raw, decrypted title keys to unlock the game files. This is where keys.txt enters. The file is a plain-text list, typically formatted as [Title ID] = [Encryption Key]. When a user loads a game into Cemu, the emulator reads this file, matches the game’s unique Title ID with the corresponding key, and uses that key to decrypt the game’s code, assets, and data stream. Without this file, a legally dumped copy of a Wii U disc is nothing more than an unreadable wall of encrypted noise. In essence, keys.txt provides the Rosetta Stone for the Wii U’s digital language. That said, many users rely on community-maintained key
A typical keys.txt file contains entries like this:
# Title keys for Cemu
d7b00402659ba2abd9cb89d354c6f7e3 # Mario Kart 8 [US]
e1e9e7b6b5a5c4d3b2a1908776655443 # The Legend of Zelda: Breath of the Wild [EU]
Each line is a hexadecimal string. The part before the # is the title key; the part after is a human-readable comment identifying the game.