ΚΕΝΤΡΟ ΜΕΛΕΤΩΝ ΑΣΦΑΛΕΙΑΣ CENTER FOR SECURITY STUDIES UKSIM-AMSS: 15 TH INTERNATIONAL CONFERENCE ON MODELLING AND SIMULATION CAMBRIDGE UNIVERSITY (EMMANUEL COLLEGE), 10 -12 APRIL, UK. SEMANTIC MODELING & MONITORING FOR REAL TIME DECISION MAKING: RESULTS AND NEXT STEPS WITHIN THE GREEK CYBER CRIME CENTRE OF EXCELLENCE (GCC)
Team Presenter: Vasilis Tsoulkas, Ph. D, Systems Analysis. Research Group: v Dimitris Kostopoulos, MSc, Software Analyst v George Leventakis, Ph. D, Security Risk Analyst v Prokopis Dogkaris, Ph. D, Security Policy Analyst v Vicky Politopoulou, MSc, Forensics Analyst v Parts of this research implemented in cooperation with : the IT Innovation Center, Southampton , UK. 2
Presentation Sections ● Motivation & Objectives – FP 7 funded - SERSCIS Proof of Concept Architecture - successfully delivered to the EC ● Semantic System Modeling Aspects (The Dynamic Multi-Stakeholder Approach) ● Semantic Monitoring and Stream Reasoning Process ● Decision Support Tool Interfaces & Risk Analytics ● Next Steps within the Greek Cyber Crime Center of Excellence (GCC). 3
Motivation and Objectives ● The FP 7 Project addressed the problem of Dynamic Modeling and Dynamic Risk Management in Critical Infrastructures (Cis). ● Today’s CIs are characterized by: Increased Connectivity (between different Stakeholders) of their Information and Data Processing Infrastructures ● …. for Increased Performance and Efficiency ● …but this situation introduces new challenges of Cyber-Physical Threats and their Counter-Measures 4
Motivation and Objectives 3 main causes for increased CI vulnerabilities 1. Cyber-Attacks against interconnected Information & Communication channels can disrupt Exchanged Data flow and Integrity 2. Local Disruption in one Organization (stake holder) generates problems elsewhere due to coupling and dependencies (of data and networks). 3. Reduced Resilience against any cyber-disruptions due to reduced excess capacity arising from the exchanged data for increased efficiency requirements 5
Objectives ● Implementation of Agile Service Oriented Technologies to ● compose ICT connections related to the critical infrastructure ● monitor and manage ICT components against well-defined dependability criteria ● adapt ICT connections in response to disruption or threats ● validation of this approach in Proof of Concept Scenarios from the air traffic sector (Airport-Collaborative Decision Making (A-CDM) /EUROCONTROL) 6
EUROCONTROL / Airport-Collaborative Decision Making – European Air Traffic Management System Data Exchange Service accessible by a consumer (aircraft operator) through SLA template consumer. The GH is responsible for coordination of Ramp Services (catering, fuelling, cleaning, baggage handling) GH: Is an Orchestrator of Ramp Services to have an aircraft ready for its next flight 7
Some Air-Traffic Critical Parameters 8
Data quality and KPIs in A-CDM ● Data: Confidentiality, Integrity, Alarms, Data Display ● KPIs: Reflect the Quality of Service Delivery ● KPIs data properties: Is the Quality of Time Estimates Accuracy Predictability Stability ● An SLA Architecture was developed with the following KPIs & Parameters in the Airport Collaborative Decision Making (A-CDM) context: • • System Availability Data Quality Data timeliness, delivery deadlines Confidentiality 9
Performance of Service Providers & KPIs ● The GH performance is characterized by two KPIs: TOBT (Target Off Block Time) i) accuracy and ii) stability; i) TOBT accuracy parameter: It is derived by comparison with a Ref. Value : Actual Ready Time (ARDT). The Mean SQ. Deviation between TOBT & ARDT is computed for all flights departing in a day. ii) TOBT stability parameter : Measures how stable is the predictor mechanism of the GH (estimates). • The two KPIs affect the number of take-offs outside a Slot Tolerance Window (STW). • Another KPI for overall CDM performance evaluation: Average Number of Slots / flight. (Ideally: One Slot/Flight) 10
Addressing the Modeling Challenge for Machine Reasoning For the Dynamic Multi-Stakeholder system we constructed : 4 -levels of abstraction 1. A core (ontology) structure: to model the System and its assets subject to threats and protected by controls 2. A dependability model: describing system independent: assets, threats, controls using OWL classes and relationships. Security expertise is encoded in this model. 3. An abstract system model: describes system-specific threats and controls. Extends the dependability model classes with security knowledge. 4. A concrete system model: provides a snapshot of the running system and instances of the participating assets + contextualised threats & controls. Each level inherits from its predecessor (parent – child relation). The final concrete model has simple structure and integrates knowledge from: Abstract system model and Dependability model. 11
Brief Analysis of Ontology & Models 1. The Semantic Ontology is constructed such that: ● Only OWL Classes are used for design-time modelling ● OWL Instances are used for modelling the Run – Time System Composition ● Security expertise is added at design time in the OWL classes 2. The Dependability model provides the first step to develop the Abstract System Model which is a Design – Time Model of the system that will be composed dynamically “On the Fly” (run-time). 3. The Concrete Model Generator is connected to the monitoring subsystem to create a model of the Running System (Current System Composition). 12
Main Innovation of the Approach ● The Modelling Semantics approach Modelling for is constructed Machine using Reasoning automated threat analysis and risk estimation when the system is composed at Run-Time. ● The design – time Service Oriented Dynamic models are abstract: They describe the structure but NOT the composition of the system which is NOT KNOWN until “Run-Time”. 13
Core System Domain Ontology ● This basic system structure, determines what reasoning is used Threat class Description Unauthorized access The service processes an unauthorised request Client Auth. N + Client from an attacker. Auth. Z Unaccountable access Type of unauthorized access, designed to get Client Auth. N + Client the service without paying for it. Auth. Z 14 01/02/2013 Controls needed
Dependability System Model (High Level View) Threat impact is described in terms of the intended (or unintended) compromise Threat activity may affect the behaviour of the asset, or controls on the asset may reduce threatens 1 Assets are sub-classed to create generic and system-specific asset types Asset affects * 1 depends on Threat * protects Control presence is determined by asset behaviour Threats are subclassed to create generic and systemspecific threat types blocks/ mitigates Control rules define which controls block or mitigate the compromise of the threatened asset Controls are subclassed to create generic control types only 15
Dependability System Model (Controls & Threats) Dependability Model Logical Asset Types & Relationships A generic model of dynamic, multi-stakeholder service-oriented systems including generic threats and threat classification (control) rules 16
Threat Types & Threat Scenario 1. 2. 3. 4. 5. Unauthorized Access (to the service) Data traffic Snooping Man in the Middle Client Impersonation Resource Failure Unauthorized Data Update at Fuelling Service 17
Dependability Model Controls (sample ) ● Controls provide defences against generic Threats Two broad categories : ● proactive controls block a threat, against the protected asset ; ● reactive controls allow the effect of a threat on the asset to be mitigated once threat is carried out. ● Mitigation and Blocking rules are of the form : Threat. Class(? t) Asset. Class(? a) threatens(? t, ? a) Control. Class 1(? c 1) protects(? c 1, ? a) … Control. Class. N(? c. N) protects(? c. N, ? a) Mitigated. Treat(? t) Threat. Class(? t) Asset. Class(? a) threatens(? t, ? a) Control. Class 1(? c 1) protects(? c 1, ? a) … Control. Class. N(? c. N) protects(? c. N, ? a) Blocked. Treat(? t) 18
Threat Block – Mitigation Rule Explanation Threat. Class(? t) Asset. Class(? a) threatens(? t, ? a) Control. Class 1(? c 1) protects(? c 1, ? a) … Control. Class. N(? c. N) protects(? c. N, ? a) Mitigated. Treat(? t) or Threat. Class(? t) Asset. Class(? a) threatens(? t, ? a) Control. Class 1(? c 1) protects(? c 1, ? a) … Control. Class. N(? c. N) protects(? c. N, ? a) Blocked. Treat(? t) ● First line in each case finds a threat instance of a specific type that threatens an asset instance of a specific type. ● Second line looks for control instances of the right types to protect the threatened asset against this type of threat. ● Last line classifies the threat as either mitigated or blocked, depending on the types of controls affording this protection 19
Control Class Explanation Control classes provide: ● generic control types that can be included directly in an abstract system model; ● descriptions of deployment actions: how to deploy the control into the real system; ● descriptions of mitigation actions: how to operate reactive controls to protect assets when a threat is carried out against them. 20
Resource Software Malfunction (Mild Error) Provider. Specified Resource threatens blocks Resource Software Malfunction protects Supplier Software Patching ● Threat ● a bug in PSResource software causes it to repeatedly produce faults ● Controls ● PSResource has Suplier Software Patching: the Supplier has a procedure to maintain the software used by the PSResource ● ensures bug fixes are applied promptly ● System specifics ● one subclass per PSResource class ● one instance per PSResource of each of the resulting classes
Abstract System Model of A-CDM ● It is a design-time model of the structure of the dynamic, multi-stakeholder service-oriented system: Input for fully automated run-time model generation and analysis Tools. It is composed dynamically at Run-Time. 22
Concrete System Model in the Overall Architecture ● A run-time model of the system, including its current composition, status and threat-related behaviours (Current System Composition) ● It is Created automatically, and it is used to provide run- time decision support 23
Classification / Estimation Blocks - Output Concrete Model : Input for a) Threat Classification & b) Threat Likelihood Estimation The output of these two tools provides: • A list of potential threats with classification • Estimates of the likelihood a threat is active or in-active A description of each Threat with impact severity • A list of controls to block or mitigate a threat and if these controls are available in the system • 24
Semantic Monitoring & Stream Reasoning Process (Initial Prototype & Limitations) This initial monitoring – reasoning process has 3 -stages: Starting point: Semantic model of the structure of the dynamical multi – stakeholder system. The model was “Abstract” based only on OWL Classes with “types of entities” but NOT YET “Entity Instances”. These are only known at Run-Time. !!! At Run-Time the Concrete System Model was Generated with OWL Instances reflecting the System Composition. Concrete Model generation used Status Monitoring Data from Run Time Monitoring and Management Block 25
Some…. . Limitations of this Approach ● Run – Time Concrete model reflects instantaneous snap-shot of System Composition, Behavior & Status. No past Information. !! ● Threat Analysis depends on Current Concrete Model and NOT on past Snap-Shots (History). !! ● Threat activity is computed from current concrete system model NOT on past Snap-Shots (History). !! ● No Correlation between Activity and different threats 26
Some…… Po. C Implementation Limitations ● A complete set of monitoring data is needed to generate the Concrete System Model Snap-shot with Re-Generation of even static features of the model each time. !!! The A-CDM Po. C. ● This generation of the Complete - Concrete Model is “Time Consuming”. Every new model is “out-dated” !! missing intermediate “rapid changes information”. • Non-Distinguishability between asset – compromises (Behaviors) that produce the same instantaneous monitoring data even for different Past Monitoring data. 27
New Approach: Stream Reasoning ● • Information arrives as a stream of “time-stamped” data • The Knowledge base can be continuously updated and reasoning goals are continuously re-evaluated as new assertions arrive • Reasoning is implemented from a Finite – Time Window and not at a Single Instant !!. • Research Efforts on Stream Reasoning is still at its First Steps and at its Infancy. 28
3 basic – steps in Stream Reasoning ● Select: Relevant Data from Input Streams by using Sampling Policies that probabilistically drop stream elements to address bursty streams of data (unpredictable peaks). ● Abstract: Sampled streams are input to Abstract block to generate aggregate events by enforcing aggregate events continuously. Output is RDF streams (ρ, τ) with ρ – RDF triple and τ – time stamp (logical arrival time of RDF statement. Use of C-SPARQL. ● Reason: RDF (Graph Streams) streams are injected into background knowledge for reasoning Incremental implementation of RDF snapshots. tasks. 29
Semantic Monitoring Block Semantic Reasoning Block …. excluded 30
Semantic Monitoring Component : DSMS - Behavior Analyser - Sequential Detection DSMS: Data Stream Management System : samples & filters monitoring data generated by Service Monitoring and Management Components. ● Usage of open-source CEP (Java - ESPER): Real Time engine that triggers Listeners or Subscribers using a tailored Event Processing Language (EPL). 31
Behavior Analyser (BA) ● Processing of multiple data streams from DSMS. Produced Output is Graph Triples (RDF). • Decides how to convert raw monitoring data into Semantic Assertions related to: Presence of Assets and Behaviors. ● The monitoring framework generates 2 – types of Time stamped RDF assertions: (1) Presence or Absence of Assets (joining or leaving the system) (2) Assertions about Measurability, Presence or Absence of Adverse Behavior of these Assets. 32
Behavior Analyser (BA) ● The BA is not only a Transcoder converting Monitoring Events to RDF graphs. ● The BA decides about the type of Behaviors (Assets and Services). ● Example: The BA is capable to determine if an Asset is Overloaded or Underperforming using Monitoring Data for Load and Performance (KPIs – SLA events). 33
Sequential (Behavior) Detection ü Well – Known Cumulative Sum (CUSUM) algorithm from the sequential statistics literature. ü In general parametric models are used ü Change in the mean of the relevant stochastic process ü We use: The non-parametric version of CUSUM 34
Sequential (Behavior) Detection Mean Value Attack Initiation Time and Detection Delay Test Statistic 35
Non-parametric CUSUM: Mathematical principles Random Sequence If We Define: The max Continuous Increment up to time n. Decision Making Rule: 0 : Normal Operation 1 : Attack Event: N is Threshold 36
DST – Tool Dynamic Interfaces Scenario: Remote exploitation on Fuelling Services Attac. K: Attacker on the Airport. Net network targets the Host of the Fuelling Service. RKE: Remote Known Exploit 37
SERSCIS DST interface (Logical Assets View) 38
DST interface (Physical Assets View) 39
DST interface - Assets Under Threat 40
DST interface (Threats Involving Selected Asset) 41
DST interface (Threat Information and Countermeasures Proposition - Zoom) 42
EU funded Project GCC: A Cyber Crime Center of Excellence for Training, Research and Education in Greece 43
Objectives ● To create a Greek Cyber Crime Centre of excellence & develop a sustainable infrastructure for GCC. ● To mobilize the Greek constituency in the area of cyber crime training, research, and education. ● To advance research in the area of cybercrime, focusing particularly in areas dealing with ● cyber attacks, ● botnet research ● Intrusion detection systems for Critical Infrastructures. 44
Work Packages GCC Project (36 months) Starting 1 st January 2013 WP 1: Management WP 2: Dissemination WP 3: Education and Training WP 4: Research 45
Work Packages GCC Project FORTH (WP 1) Management Website(pub. /priv. ) (WP 3) Repository (University, LEAs) (WP 4) Research (Disruptive monitoring, Botnet Detection tool) AUTH (WP 3) University courses (WP 4) Legal issues SAFENET (WP 2) Dissemination Advisory Board 2 CENTRE - CCUs KEMEA (WP 3) Training (LEAs, Private/Public sector) (WP 4) Research (legal framework, Policy) Research (Intrusion Detection. System –Critical infrastructure taxonomies) 46
GCC ● A Cyber. Crime Center of Excellence for Training, Research and Education in Greece”. ● Funded under Prevention of and Fight against Crime (ISEC) Programme of European Commission Directorate-General for Home Affairs. ● GCC main objectives are to create a constituency of Greek stakeholders in the area of Cyber Crime and to mobilize this constituency to work together in education and research areas. 47
Next Steps in the GCC framework ● Exploitation of sequential detection of a change using the nonparametric CUSUM in the Behavioral Analyzer. ● Situational Awareness of the Operators using user friendly Dynamic Support Tool (DST) interfaces ● Further development using additional detection approaches (Sequential Probability Ratio Test, Different Optimality Criteria such as: Lorden, Shiryaev - Roberts) ● Distributed Real Time Sequential Detection & Hypothesis Testing for Intrusion Attacks ● Some Application areas: Industrial CIs Protection, Network Intrusion Detection Systems, Swarms & Networks of cooperative UAVs. 48
Conclusions ● Implementation of an Intelligent Prototype Tool for the Protection of Dynamic Multi Stakeholder SOA Critical Infrastructures. Air-traffic Management Systems Po. C. ● Implemented: An Innovative core ontology model which has been reinforced with rules and classes that improve threat estimation and classification. ● Implemented: Advanced Stream (RDF) Reasoning – and Behavioral Analysis Algorithms. ● Sequential data analysis led us to Advanced Semantic Stream Reasoning for Real –Time Processing. ● Implemented: Dynamic User Interfaces with Risk – Threat Analytics in Real Time for A-CDM (Eurocontrol). 49
Questions – Discussion. Thank you ! Contact Details: Vasilis Tsoulkas tsoulkas. kemea@gmail. com Dimitris Kostopoulos dimkostopoulos@gmail. com George Leventakis george. leventakis@gmail. com Prokopis Drogkaris prokopis. drogkaris@gmail. com Viky Politopoulou v. politopoulou@gmail. com 50
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