Challenges in Protecting SCADA Systems

Andrew Wright,
Cisco Systems
10am May 5
3405 Siebel Center

Abstract

Supervisory Control And Data Acquisition (SCADA) Systems are computer control networks that are used throughout our nation's electric, gas, oil, water, and waste water infrastructures to monitor and control remote field devices such as circuit breakers, pressure valves, and flow control valves. Most SCADA systems in place today use relatively old computing and communication technologies: 80386 processors and 1200 baud communication lines are common. These networks have little protection from cyber attack other than their proprietary and esoteric nature. Recent accidental events such as the 2003 northeast blackout have illustrated the delicate interdepencies between different infrastructures, and thus elevated concerns about cyber attacks on SCADA systems. While SCADA systems and protocols are beginning to migrate to IP-based solutions, the sheer number and cost of such systems in deployment guarantees they will be part of our nation's critical infrastructure for many years to come.

Cisco is participating in an effort sponsored by the American Gas Association (AGA) to develop a cryptographic protocol to protect SCADA communication lines. This effort is aimed at developing a retrofit solution to protect existing SCADA systems that are already in place. The constraints of a retrofit solution render existing cryptographic protocols such as SSL impractical, and impose some challenging requirements on the design of a suitable protocol.

This talk will give an overview of SCADA systems, describe the constraints of a retrofit protection solution, and discuss the issues involved in designing a suitable protocol. Several interesting problems arise that have received little attention from the cryptography community, and we will describe these problems in detail.