A user-customizable locking assembly includes a user-customizable key, a user-customizable key receiver, and a key receiver receptacle. Each of the user-customizable key, a user-customizable key receiver, and a key receiver receptacle includes a physical unclonable function (PUF) circuit configured to provide a PUF response in response to receiving a challenge signal. The PUF circuits of the user-customizable key and a user-customizable key receiver include personalization fuses that allow a user to further personalize or change the PUF response produced by the corresponding PUF circuits. The key receiver receptacle also includes anti-theft fuses, which are activated if the user-customizable key receiver is removed from the key receiver receptacle. In use, a protected system may utilize the PUF responses from the each of the PUF circuits to authenticate the user-customizable locking assembly.