Availability Study of the Italian Electricity SCADA System in the Cloud

Transcription

1 Availability Study of the Italian Electricity SCADA System in the Cloud Stefano Sebastio a, Antonio Scala b,a, and Gregorio D Agostino c,a a LIMS London Institute of Mathematical Sciences, London, UK b ISC-CNR Sapienza Università di Roma, Rome, Italy c ENEA, CR Casaccia, Rome, Italy

2 Outline Scenario and motivation Hierarchical structure for a nationwide SCADA and cloud deployments Availability computation Results Conclusion 2 / 15

3 ICS and EMS/SCADA Industrial Control System (ICS): control architecture in industrial sectors, utilities and critical infrastructures Energy Management System/Supervisory Control And Data Acquisition (EMS/SCADA): computer aided-tools for Infrastructure tuning (over short and long periods) Ensure service availability and reliability Enhancing Quality of Service (QoS) Metering and monitoring the network for displaying or recording functions the control centers in SCADA systems collect and log information gathered by the field sites, display information to the HMI, and may generate actions based upon detected events are also responsible for centralized alarming, logging, historical data archiving, trend analysis and reporting" [NIST Tech. Rep., «Guide to ICS security SCADA, DCS, and other control system configurations such as PLC», 2011 ] 3 / 15

4 Risks and Vulnerabilities Physical vulnerability to: extreme weather conditions (e.g., floods, windstorms, hurricanes, prolonged droughts that trigger wildfires) [Hurricane Sandy, 2012] attacks [Metcalf sniper attack, 2013] Cyber attack (Modbus, DNP3, IEC protocols designed without security in mind) [Cyber attack on Ukraine s power grid, 2015] Interdependency power/telecom [2003 Italy blackout] 4 / 15

5 Ongoing Changes and Opportunities Green policies pushing small-scale grid-connected decentralized generation of power from renewable sources (e.g., solar, wind, geothermal, fuel cells and biomass) -> prosumer Smart meters with huge amount of data to be stored, analysed and accessed frequently blurring the distinction on the once siloed utility operational technologies (OT) and information technology (IT) infrastructures Need for: Improved resiliency Integration of decentralized power generation Increasing the geographical-distribution of power generation, sensors and communications networks: From Modbus, DNP3, IEC protocols to TCP/IP Pledging a future with autonomous power rerouting in case of faults 5 / 15

6 The Hierarchical SCADA system Italian case Remote units (RU) or terminals: Real-time interventions on voltage to manage load and events of interruptions Regional Control Center (RCC): group and supervise RUs in larger geographical zones National Center (NC): gathering data from and dispatching relaxed timing commands to RCCs & non time-critical operations (e.g., command planning, critical events analysis and statistics) ENTSO-E Connections of interest On a virtual proprietary network 6 / 15

7 Cloud OK, but SCADA in the Cloud? Cloud paradigm and its taxonomy: Physical deploy Software abstraction Opportunities and challenges: From CapEx to OpEx model IT consolidation Network & control performance Data security and privacy System downtime and reliability Solutions: Real-time nosql In Memory-DB Searchable encryption Private information retrieval Hot-standby configuration 7 / 15

8 Cloud Deployments for a Nationwide SCADA Data analytics & data access Real-time command and historical data on cloud 8 / 15

9 Availability Fraction of time the system is operational: identifying the functional blocks (in network can be both nodes and links), modeling their relationship and availability from experiments, information from technology vendors/adopters or assumptions Single failure: Fully-disjoint paths: Multiple simultaneous failures: Partially link-disjoint: 9 / 15

10 Availability Model for an Optical Network Tornatore, M., Maier, G., Pattavina, A., Availability Design of Optical Transport Networks, IEEE Journal on Selected Areas in Communications, / 15

11 Approximate Availability Computation An approximate algorithm for an NP-hard problem 11 / 15

12 Availability Analysis 2 days 6 mins 3mins 13 hours 12 / 15

13 Reliabiltiy analysis Robustness analysis (k out-of N) 13 / 15

14 Conclusion Many ongoing changes and opportunities in the Grid (smart- and micro- grid, cloud adoption) Availability study for the SCADA system managing the electricity grid in Italy Lack of real data (for confidentiality reasons) and involvement of CI operators but the purpose of this work is to scrape the surface of the problem, turning attentions and fostering discussions towards the ongoing change to one of the most critical infrastructure 14 / 15