...................................................................................................................................... iv Table of Contents ...................................................................................................................... v List of Figures ........................................................................................................................... xi Chapter 1. Introduction ......................................................................................................... 1 1.1 Problem Statement .................................................................................................... 2 1.2 Contribution ................................................................................................................ 3 1.3 Thesis Organization .................................................................................................. 4 Chapter 2. Background .......................................................................................................... 6 2.1 Origins of SCADA ........................................................................................................ 7 2.2 SCADA Architecture ................................................................................................... 8 2.2.1 Control Center ................................................................................................................................... 8 2.2.2 Operator Interface ........................................................................................................................ 10 2.2.3 Field Devices ................................................................................................................................... 10 2.3 Wide-‐Area SCADA Networks ............................................................................... 11 2.3.1 Wired Communications .............................................................................................................. 11 2.3.2 Wireless Communications ......................................................................................................... 11 2.4 Common SCADA Communication Protocols ................................................... 12 2.4.1 Modbus Protocol ............................................................................................................................ 12 2.4.2 DNP3 Protocol ................................................................................................................................ 13 2.5 SCADA Convergence ............................................................................................... 14 Chapter 3. SCADA and Security ........................................................................................ 16 3.1 Current State of SCADA Security ........................................................................ 16 3.1.1 The Importance of SCADA Security ....................................................................................... 17 3.1.2 SCADA Security Incidents .......................................................................................................... 18 3.1.3 SCADA Security Standards ........................................................................................................ 19 3.1.3.1 NIST System Protection Profile .......................................................................... 20 3.1.3.2 ISA-‐SP99 ....................................................................................................................... 20 3.1.3.3 AGA-‐12 Documents .................................................................................................. 20