Fast cryptographic key generation from memristor-based physical unclonable computed functions

Systems and methods for symmetric encryption between a client and a server device include a client device having an array of physical unclonable function devices and a server device storing information sufficient to reconstruct responses of the devices to an applied stimulus such as varying levels of electrical current. The server shares a challenge with the client, which measures characteristics such as electrical resistances for a subset of the devices according to instructions extracted from the challenge. The client measures a corresponding reference device in the array for each device of the subset and assigns a value determined based on a comparison of each device with the corresponding reference device to generate a cryptographic key. The server calculates an expected response of the client to the challenge according to a model of the devices in the array, and uses the calculated response to generate the key independently.