Northern Arizona University

Dennis D Booher

Bertrand Francis Cambou

Christopher Robert Philabaum

Systems and methods of authentication and encrypted communication between a server and client devices using independently-generated shared encryptions keys are disclosed. Client devices with arrays of physical-unclonable-function devices are respond to challenges from a server. Characteristics of the arrays are stored by the server during a secure enrollment process. Subsequently, the server issues challenges to the clients. The clients derive encryption keys from their responses to those challenges generated by the clients from characteristics of portions of the arrays specified by the challenges. The clients send messages encrypted with the client-generated encryption keys to the server. The server uses the stored characteristics to independently reproduce the client-generated encryption key. When the server-generated encryption key matches the client-generated key, the clients may be authenticated and the clients can communicate securely with the server without exchanging encryption keys. Ternary PUF characterization schemes may be used to achieve acceptable authentication error rates.

Response-based cryptography using physical unclonable functions

A system and method for the generation of composite private keys are provided. First and second bitstreams are retrieved from an addressable cryptographic table by deriving addresses in the addressable cryptographic table from an initial instruction, accessing first and second bit values stored at addresses belonging to the derived addresses in the addressable cryptographic table, and outputting the first bit values as the first bitstream and the second bit values as the second bitstream. The first bitstream is concatenated with data from the first bitstream to form a data stream having a desired length and the second bitstream is concatenated with data from the second bitstream to form a selector stream having the desired length. A first composite encryption key having a length longer than the first and second bitstreams is formed by selecting values of the data stream identified by corresponding bit values of the selector stream.

Growing community of inventors

Flagstaff, AZ, United States of America

Dennis D Booher