ISL Colloquium: Security using physical dynamics

Security using physical dynamics
Thursday, April 23, 2015 - 4:15pm to 5:15pm
Packard 101
Professor Suhas Diggavi (UCLA)
Abstract / Description: 

In this talk, we explore how physical resources and dynamics can be an enabler in enhancing security. We illustrate this through results in two topics: wireless network security and security in cyber-physical systems.

Wireless networks provide plentiful resources to construct security: the existence of feedback (today part of all wireless standards); the possibility of selecting and using multiple paths; the smart use of wireless jamming; the wireless channel variability and unpredictability. Individually each of these properties has been identified as enabling security, and interesting results over specific network topologies have been developed, but we do not yet have a unifying theory that links all of them together. In this talk we describe our first steps on building such a framework for erasure networks, which capture many of the important characteristics, but are more tractable to analyze. We develop several results for interactive security for this model, including group key generation, message security, private message broadcasting and oblivious transfer. We will describe some mechanisms that can create erasure channels starting from wireless physical channels. We will then describe our experience in validating some of these results through preliminary experimental results on a test bed.

Critical physical infrastructures, such as electrical grids and water networks etc., are increasingly controlled through a distributed cyber-systems which make it vulnerable to attacks. For CPS security, just protecting bits is insufficient as sensor attacks can manipulate physical signals before its conversion to bits, rendering cyber-encryption ineffective. By drawing insights from error correction, we develop defense strategies that utilize the physical dynamics of CPS. We demonstrate this for the state estimation problem in the presence of attacks on sensors and actuators and characterize the resilience of a system which corresponds to the maximum number of attacks that can be tolerated while successfully reconstructing the state from observations.

This talk is joint work with L. Czap, C. Fragouli, V. Prabhakaran, S. Mishra. H. Fawzi, Y. Shoukry, N. Karamchandani and P. Tabuada. Some parts are also joint work with K. Argyraki, B. Dey and M. Mishra.

Refreshments will be served after the talk.