October 24 – November 11, 2016 Albuquerque, New Mexico ... · Example: PPS Response Time = 90 sec...

20 – Path Interruption Analysis

The Twenty-Sixth International Training Course

20. Pa th In te r rupt ion Ana lys i s

October 24 – November 11, 2016Albuquerque, New Mexico, USA

Mark Snell

Path Interruption Analysis

S tudent Learning Object ives

After completing this module, you should be able to:

• Define an adversary path• Identify an adversary timeline and response timeline• Construct an adversary timeline and a response timeline• For an adversary timeline and response timeline

• Determine the Critical Detection Point (CDP) • Calculate Probability of Interruption, PI

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INFCIRC 225 Revis ion 5 References

• 3.13 The state should ensure that evaluations include exercises to test the physical protection system, including the training and readiness of guards and/or response forces.

• 3.29 The operator should develop and implement means and procedures for evaluations, including performance testing, and maintenance of the physical protection system.

• 4.35 Evaluations should be conducted regularly to determine reliability and effectiveness against the threat.

• 5.16 If the evaluation of the design of physical protection system indicates that it is ineffective, then the operator should redesign the physical protection system and re-evaluate its effectiveness.

3


Adversary Path Def in i t ion

Adversary Path: A time-ordered sequence of path elements, areas, and a target task that the adversary must traverse to complete an attack from Offsite to the chosen target

Adversary paths are defined using an Adversary Sequence Diagram

4Target in Floor Vault

Secure Room Wall

Secure Room

Offsite

Door 2

Reactor Area

Building Door

Reactor Building

Personnel Portal

Research Complex

Facility Fence

Site Campus




Purpose of Path Interrupt ion Analys is

Path Interruption Analysis: Determines whether detection and delay are sufficient along all adversary paths to provide an adequate level of Probability of Interruption, PI,• This is effectively a timeline analysis comparing adversary and

response timelines for each path to determine PI

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Adversary Timel ine and Response Timel ine• Adversary timeline is based upon adversary tasks• Response timeline is based on Detection and Response Times

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Detection Time

Adversary Completes Task

Time

AdversaryBegins Task

Adversary Timeline

Ad

vers

ary

Det

ecte

d

Response Time

Ad

vers

ary

Inte

rru

pte

d

PPS Response Time*

Sensing Opportunities

*Response Force Time




Example Set o f Adversary T ime l ine In format ion

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Time Estimate

Task

Minimum Time

(seconds) Task

1 2

12 12

Penetrate fence Transit time

Cumulative Time

(seconds)1224

180

3 48 Penetrate Outer door 72 4 5 6 7 8

24 12

6 12 54

Transit timePenetrate Inner doorTransit time to container Open container and gather material Escape Total (approx. 3 minutes)

96 108 114 126 180

AreaAccess Building

Access

RoomAccess

ContainerAccess Sensitive

Material

TotalTime3 Minutes

Task1

Task2

Task6

Task 8

Task4

Task3

Task7

Task5


Example Set o f Adversary T ime l ine In format ion: Assoc ia ted Adversary T ime l ine

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Time Estimate

Task

Minimum Time

(seconds) Task

1 2

12 12

Penetrate fence Transit time

Cumulative Time

(seconds)1224

180

3 48 Penetrate Outer door 72 4 5 6 7 8

24 12

6 12 54

Transit timePenetrate Inner doorTransit time to container Open container and gather material Escape Total (approx. 3 minutes)

96 108 114 126 180

Task delay times

Sensing opportunities between tasks




Example Set o f Response T ime l ine In format ion

• The PPS Response Time is the sum of the times for all response actions performed by the response

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Response Action Patrol Team 1

Alarm communication time 1 1

Alarm assessment time 29 29

Response force communication time 10 10

Response force preparation time 0 20

Response force travel time (vehicle) 30 15

On‐site deployment time 10 15

PPS Response TIme (Total) 80 90

Average Response Times

(in seconds)


The PPS Response T ime i s the Sum of a Detect ion T ime and a Response T ime

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Example: PPS Response Time = 90 sec

Detection Time = 30 sec

Response Time = 60 sec




Adversary T ime l ines and Response T ime l ines Can Then Be Combined onto the Same D iagram

Response Timeline Information

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Adversary Timeline Information


M in imum Probab i l i t i es o f Detec t ion , PD, Are A lso Needed for Each Task

AreaAccess Building

Access Room

Access

ContainerAccess Sensitive

Material

TotalTime

3 Minutes

Task1

Task2

Task6

Task 8

Task4

Task3

Task7

Task5

PD = .8

PD = .6

PD = .5

Minimum Probabilities of Detection depend upon performance tests for specific adversary defeat methods

PD = .6

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Ca l cu la t ing Probab i l i ty o f In ter rupt ion for an Adversary T ime l ine and Response T ime l ine

• Review of Terminology Timely detection Critical Detection Point (CDP)

• Formulas for calculating Probability of Interruption based on timelines

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Terminology

Timely Detection: A sensing opportunity on a path is timely ifPPS Response Time Is Less than the Adversary Task Time Remaining

After First Sensing

Critical Detection Point (CDP): Last sensing opportunity on a path at which detection can occur in time for response force to interrupt the adversary

Relationship to Timely Detection: The CDP is the last sensing opportunity that provides timely detection

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Us ing Adversary and PPS T ime l ines to F ind the Cr i t i ca l Detec t ion Po in t

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AdversaryBegins Task

Adversary Completes Task

Time

Adversary Task Time

CT

PPS Response Time

Adversary Task Time Remaining After First Sensing

PPS Response Time

PPS Response Time



CDP

Sensing opportunities thatprovide timely detection


P robab i l i ty o f In ter rupt ion , P I, Depends Upon Where the CDP i s on the Path

Probability of Interruption (PI) : The cumulative probability of detection up to and including the CDP

PI = 1 – (1-PD1)*(1-PD2)*…(1-PDCDP) where

• PDj is the Probability of Detection at the jth opportunity• PCDP is the Probability of Detection at the CDP

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ExampleAdversary Task TimePD1=.8 PD2=.6 PD3=.6

Assume the 3rd sensing opportunity is the CDP

PI = 1 – (1-PD1)*(1-PD2 )*(1-PD3) = 1-(1-.8)(1-.6)(1-.6) = .97



Start Path

Complete Path

Adversary Chooses Defeat Methods That

Minimize Delay

Adversary Uses Defeat Methods That Minimize Detection Probability

PPS Response Time

Time Remaining Along Path

Critical Detection

Point

Probability of Interruption, PI


P robab i l i ty o f In ter rupt ion , Mode l Assumes Min imum De lays Af ter the CDP and Min imum PD’s up to/ Inc lud ing the CDP

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Adversary Task Time


To Determine Probab i l i ty o f In ter rupt ion , P I fo r a Path

• Create an Adversary Timeline Using Minimum Delay Times and Probabilities of Detection

• Determine the CDPStep 1: Sum delays from the end of the timelineStep 2: Stop when sum exceeds the PPS Response TimeStep 3: Assign CDP to last timely element/area

• Calculate PI as the cumulative probability of detection to the CDP

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T ime ly Detec t ion Example: Adversary and Response T ime l ines

Penetrate Fence

Transit time

Penetrate Outer Door

Transit time

Penetrate Inner Door

12 sec

12 sec

48 sec

24 sec

12 sec

TaskDelay

Time (Seconds)Detection

Probability, PD

0.8

0.6

0.6

0.2

0.5

Transit time

Gather material

Escape

6 sec

12 sec

54 sec

0.1

0.9

1.0

The Task Delay Times and PD’s Are Shown Vertically:

PPS Response Time = 90 sec 19


T ime ly Detec t ion Example—Base l ine Vers ion

Penetrate Fence

Transit time


Transit time


12 sec

12 sec

48 sec

24 sec

12 sec84

72

66

PPS Response Time = 90 sec

TaskDelayTime

Detection Probability,

PD

0.8

0.6

0.6

0.2

0.5

Transit time

Gather material

Escape

6 sec

12 sec

54 sec

0.1

0.9

1.0

Adversary Task Time Remaining

After First Sensing

108

0

54

(CDP)

• Step 1: Determine the CDP based on Adversary Task Time Remaining:

• Step 2: Calculate Probability of InterruptionPI = 1 – (1-PD1)*(1-PD2 )*(1-PD3) = 1-(1-.8)(1-.6)(1-.6) = .97

At CDP, Adversary Task Time Remaining Is Greater than the PPS Response Time

PD’s are timely

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Upgrad ing Ru les for Increas ing P I a long a Path

• Increase timely detection before/at the CDP Add detection before/at the CDP

• Move the CDP closer to the end of the path, making more sensing opportunities timely Increase delays after the CDP Decrease PPS Response Time

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T ime ly Detec t ion Upgrade Example—To Inc rease P I, Inc rease PD befo re o r a t the CDP

Penetrate Fence

Transit time


Transit time


12 sec

12 sec

48 sec

24 sec

12 sec84

72

66


TaskDelayTime


PD

0.8

0.6

0.9

0.2

0.5

Transit time

Gather material

Escape

6 sec

12 sec

54 sec

0.1

0.9

1.0

Adversary Task Time Remaining After First

Sensing

108

0

54

(CDP)


• Step 2: Calculate Probability of Interruption

PI = 1 – (1-PD1)*(1-PD2 )*(1-PD3) = 1-(1-.8)(1-.6)(1-.9) = .992


PD’s are timely

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T ime ly Detec t ion Upgrade Add ing PD a f te r the CDP Does Not Inc rease P I

Penetrate Fence

Transit time


Transit time


12 sec

12 sec

48 sec

24 sec

12 sec84

72

66


TaskDelayTime


PD

0.8

0.6

0.6

0.2

0.9

Transit time

Gather material

Escape

6 sec

12 sec

54 sec

0.1

0.9

1.0


Sensing

108

0

54

(CDP)



PI = 1 – (1-PD1)*(1-PD2 )*(1-PD3) = 1-(1-.8)(1-.6)(1-.6) = .97


PD’s are timely

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T ime ly Detec t ion Upgrade Example—To Try To Increase P I, Add De lay a f te r the CDP

Penetrate Fence

Transit time


Transit time


12 sec

12 sec

48 sec

24 sec

12 sec

88 PPS ResponseTime = 90 sec

TaskDelayTime


PD

0.8

0.6

0.6

0.2

0.5

Transit time

Gather material

Escape

6 sec

34 sec

54 sec

0.1

0.9

1.0


Sensing

0

54

(CDP)



PI = 1 – (1-PD1)*(1-PD2 )*(1-PD3) *(1-PD4)*(1-PD5) = 1-(1-.8)(1-.6)(1-.6)(1-.2)(1-.5) = .987


92

PD’s are timely

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T ime ly Detec t ion Upgrade Example—Add ing De lay be fo re o r a t the CDP Does Not Change P I

Penetrate Fence

Transit time


Transit time


12 sec

12 sec

96 sec

24 sec

12 sec


TaskDelayTime


PD

0.8

0.6

0.6

0.2

0.5

Transit time

Gather material

Escape

6 sec

12 sec

54 sec

0.1

0.9

1.0


Sensing

84

72

66

108

0

54

(CDP)



PI = 1 – (1-PD1)*(1-PD2 )*(1-PD3) = 1-(1-.8)(1-.6)(1-.6) = .97


PD’s are timely

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T ime ly Detec t ion Upgrade Example—To Try To Increase P I, Decrease the PPS Response T ime

Penetrate Fence

Transit time


Transit time


12 sec

12 sec

48 sec

24 sec

12 sec

66 PPS ResponseTime = 70 sec

TaskDelayTime


PD

0.8

0.6

0.6

0.2

0.5

Transit time

Gather material

Escape

6 sec

12 sec

54 sec

0.1

0.9

1.0


Sensing

0

54

(CDP)



PI = 1 – (1-PD1)*(1-PD2 )*(1-PD3) *(1-PD4)*(1-PD5) = 1-(1-.8)(1-.6)(1-.6)(1-.2)(1-.5) = .987


72

PD’s are timely

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Summary: Path Interrupt ion Analys is

With respect to our Learning Objectives:• An adversary path is defined as:

• “A time-ordered sequence of path elements, areas, and a target task that the adversary must traverse to complete an attack”

• Adversary and response timelines show Times and sensing opportunities based upon

adversary tasks

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PPS Response Time based on Detection and Response Times• Adversary timelines are constructed based on task delays and

detection probabilities for the adversary path• Response timelines are constructed based on time estimates for

all response actions


Summary: Path Interrupt ion Analys is

With respect to our Learning Objectives:• To determine the CDP based on adversary and response

timelines:First: Sum delays from the end of the adversary timelineNext: Stop when sum exceeds the PPS Response TimeLast: Assign CDP to last timely element/area

• Calculate PI as the cumulative probability of detection up to and including the CDP:PI = 1 – (1-PD1)*(1-PD2)*…(1-PDCDP) where

• PDj is the Probability of Detection at the jth opportunity• PCDP is the Probability of Detection at the CDP

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October 24 – November 11, 2016 Albuquerque, New Mexico ... · Example: PPS Response Time = 90 sec...

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