Examples of computing devices for authenticating a write request to a controller of a computing device are described herein, in an example, a computing device may include a controller having a first authentication key and a firmware having a copy of the first authentication key. The copy of the first authentication key being editable. The controller may randomly generate a second authentication key. Using the first authentication key and the second authentication key, the controller may compute a first hash value. The firmware may compute a second hash value using the copy of the first authentication key and the second authentication key. When the controller receives a write request, the controller may compare the first hash value and the second hash value and allow the write request upon successful comparison.