Abstract: Systems and methods for cryptographic key generation at a client and server are disclosed. The client has an array of PUF devices, and the server has an image that PUF. The server sends the client addresses of PUF devices to be measured, and retrieves previously stored responses corresponding to those addresses from its database. The client measures responses at the addresses. Each device hashes the resulting responses, and the server compares the hash received from the client to its own. If the hashes to not match, the server searches for a matching hash be perturbing the measured response bit stream until a match is achieved. The perturbed response bitstream, and the measured response at the client are then salted, and used for key generation.