There are lots of encryption keys used on the Wii U. They're seperated into two types, Espresso and Starbuck (for the normal and security processors), aside from a few exceptions. Only SHA1 hashes will be posted here, but several keys are publicly available, as it's possible to dump the Espresso key bank from the OTP. See Fail0verflow's writeup for more details.
The Espresso keybank is 64 bytes, with the first 32 being the Ancast Keys. After the Boot ROM reads these keys, it disables access until the Espresso is reset again.
vWii Ancast Key
Wii U Ancast Key
Used by the Espresso Boot ROM to decrypt the Cafe OS kernel at load time.
Wii U common key
Used to decrypt the title key for every Wii U application. System titles and installable applications are decrypted at install time, disc-based games are decrypted at load time.
Cafe OS and Starbuck binaries are double-encrypted with this and the Starbuck Wii U Ancast Key.
vWii common key
Used to decrypt the title key for vWii system updates (as part of the Wii U's update process, meaning vWii doesn't have access to it).
Wii U ancast key
boot1 ancast key
Used by boot0 to decrypt boot1 on boot.