Systems and methods of improving public key infrastructure using PUF arrays are disclosed. The systems and methods are usable to improve PKI based on Lattice and Code cryptography. In the disclosed system, a client device includes an enrolled PUF array, and a server device acting as a Certification Authority includes an image of the PUF array including previously measured responses data for the devices in the PUF array. The CA sends a set of addresses to the client device, which generates a public key from measuring the response of PUF devices with the addresses. The CA receives the generated public key, and determines that the enrolled PUF was used to generate the key.