CIF: EAGER: Everlasting Security in Disadvantaged Wireless Environments

University Of Massachusetts Amherst, Amherst MA

Investigators

Abstract

This project develops a new approach to protecting information from interception by adversaries in wireless communication networks, with a particular focus on the scenario where an eavesdropper obtains a higher-quality version of the transmitted signal than the desired recipient. The standard method of providing protection in such a situation is to encrypt the information so that it is beyond the eavesdropper's computational capabilities to decrypt the message; this approach has met with longstanding critiques, including the lack of a fundamental proof establishing the difficulty of the problem presented to the adversary. An approach to everlasting security initiated in this project exploits the non-commutativity of certain nonlinear operators: different orderings of the same two nonlinear systems applied to the same input signal can produce different outputs. This property is exploited for security in wireless communication links by employing a short-term cryptographic key to force the eavesdropper's signal to be subjected to nonlinear operations in the reverse order of that of the signal at the desired recipient. The appropriate design of the nonlinear systems yields differences in the signals at the desired recipient and eavesdropper that can be exploited for everlasting secrecy - even when the ephemeral cryptographic key is revealed to or broken by the eavesdropper immediately after transmission. The development of this approach under applicable system constraints and a comparison of the obtained security performance to current approaches form the technical core of this project. By establishing a new approach that expands the system conditions under which everlasting security is obtained, a new avenue of research opens in this critical area of wireless security. In particular, a security approach that exploits characteristics of the eavesdropper's receiver rather than assumptions of noise or loss on the propagation channel will provide an extra layer of security that has not been exploited in current systems. Also, integral to the project is the involvement of undergraduate and graduate students, and a research experience for high school teachers will draw technical ideas from the project. These activities provide workforce development in a critical area by providing a compelling application and further broaden the impact of the project.