Visualizing NISTIR 7628, Guidelines for Smart Grid Cyber Security

Matthew Harvey; Daniel Long; Karl Reinhard University of Illinois Urbana-Champaign, Dept. of Electrical Engineering

Abstract— The National Institute of Standards and Technology Interagency Report (NISITR) 7628, Guidelines for Smart Grid Cyber Security, provides an analytical framework that stakeholders can use to develop effective Smart Grid related characteristics, risks, and vulnerabilities. NISTIR 7628 spans more than 600 pages and is densely packed with technical information drawn from multiple disciplines, which to many readers is difficult to broadly conceptualize and apply. This paper explores methods for visualizing the complexities of NISTIR 7628’s cyber security guidelines for the nascent Smart Grid and aiding readers to better synthesize the information presented.

I. INTRODUCTION The United States and other advanced industrial countries around the world have embarked upon a long term effort to modernize their electric power infrastructures. This modernization effort includes applying advanced digital technologies to systems to expand communications and control over very large systems to achieve ever increasing efficiency while maintaining very high reliability. The broad application of digital technologies is accompanied by increased exposure to malicious attacks upon the power grid's digital infrastructures. As the digital infrastructure expands, the exposure to and consequences of compromise also expand.

In August of 2010, the National Institute of Standards and Technology (NIST) Computer Security Division published NISTIR 7628, Guidelines for Smart Cyber Security, which expands upon the Smart Grid cyber security principles published in NIST's 2010 Special Publication 1108, NIST Framework and Roadmap for Smart Grid Interoperability Standards. NISTIR 7628 synthesizes the input of more than 500 stakeholder representatives from the private sector (including utilities, vendors, manufacturers, and electric service providers), various standards organizations, academia, regulatory organizations, and federal agencies. The guidelines represent power, computer, information technology, and telecommunications industry perspectives. The document is a first effort to develop a technical, analytical framework needed to inform individuals and organizations responsible for addressing cyber security for Smart Grid systems and its constituent hardware and software components. The document is envisioned as a first step in evolutionary series of documents that will produce standard protocols, interfaces, and technical specifications needed for a secure Smart Grid.

The document focuses exclusively on the cyber-security aspects and does not address physical security requirements.

II. NISTIR 7628

A. NISTIR Diagrams NISTIR 7628 conceptualized the power grid at the higest

level as being composed of seven Domains: marketing, operations, sevice provider, bulk generation, transmission, distribution, and customer as seen in Fig. 1. A Smart Grid domain is a high level grouping of orgainizations, buildings, individuals, systems, devices with similar objectives or functions.

Fig. 2 shows 46 actors that comprise the seven domains. Actors are devices, systems, or programs that make decisions and exchange the information necessary for the Smart Grid to function. This actors list is intended to be comprehensive, but not all inclusive, as this model represents diverse real-world organizations that are uniquely purposed and organized . The Logical Reference Model show in Fig. 3 depicts 130 logical interfaces (interactions between actors. The obvious challenge posed by this representation’s complexity is for users to translate its high level abstractions into implementable policies and procedures on their organizations information processing systems (hardware, software, network, etc.)

To aid this synthesis, NISTIR 7628 identifies 22 logical

Fig. 1 Interactions of Actors in Different Smart Grid Domains through Secure Communications Flows [1]

Submitted for publication. Author copy – do not redistribute.

interface categories that group logical interfaces based upon similar attributes affecting cyber security requirements; the logical interface categories are listed and described in Table 2-2. The grouping criteria include the three traditional Information Assurance dimensions: confidentiality, integrity,

and availability. Other criteria include domain and logical interface information content. Each logical interface can be thought of as a layer in a three dimensional representation. As an example, Fig. 4 provides a graphical depiction of Logical

Fig. 2 Composite High-level View of the Actors within Each of the Smart Grid Domains [1]

Fig. 3 Logical Reference Model [1]

Interface 6, which shows the interfaces between control systems (actors) in organizations in 3 domains.

In addition to the Logical Interface Categories defined in Chapter 2, NISTIR identifies 10 architecturally significant Use Cases that involve different actor and logical interface sets, which have similar complexity and graphical representations. These Use Cases include: advance metering architecture (AMI), Demand Response, Customer Interfaces, Electricity Market, Distribution Automation, Plug-in Hybrid Electric Vehicles (PHEV), Distributed Resources, Transmission Resources, Regional Transmission Operations / Independent System Operators (RTO/ISO), Operations, and Asset Management.

Over the course of 3 years of association with the TCIPG Project and studying NISTIR 7628, we have observed that the document was prepared by experts from three very disparate disciplines: power system engineers, computer and network engineers, and information technologist. There are relatively few experts in these disciplines with overlapping knowledge that bridges the gaps between these disciplines. Consequently, for most readers, the task of making sense of the very detailed and often unfamiliar information is quite daunting.

As a team, we have detailed knowledge of power systems but less knowledge of computer engineering and information management technologies. Therefore, our interest is developing a resource that dramatically accelerates the process of assembling data and information to facilitate synthesizing the complex ideas and relationships necessary to improve cyber security. We believe innovative approaches to visualizing NISTIR 7628’s content would be a big step forward. Further, the user must be able define and adapt the

visualizations appropriate to his own knowledge base and purpose. We also envision the user being able to leverage other resources to seamlessly assemble other information appropriate to their purpose.

III. VISUALIZING NISTIR 7628 Our research vision is to create user controllable visual

representations of the information in NISTIR 7628 to enable cyber security. The interactive interface would enable the user to organize information to provide insights that would otherwise be difficult to reach; this includes controlling the content and detail of information presented. For instance, we envision aiding the identification of common requirements across different Logical Interface Categories and Use Cases by displaying only that information. We also envision aiding the identification of common requirements across different Logical Interface Categories and Use Cases by displaying only that information. We also envision being able to pull-up and drill-into detailed information not a part of the current view – and open and close other related information as needed.

Our first small step to achieving this vision was to explore ways to stack select logical interface categories as distinct data layers. For example, consider the stacked Logical Interface Categories shown in Fig. 5 – an oblique visualization of several logical interface categories from pages taken directly from the document. This is helpful to illustrating the concept, but not very practical from productive use. We have developed two applications to explore implementing our ideas: 1) a web-based HTML application and 2) a MATLAB-based application leveraging 3D graphing capabilities. A. HTML Web Page Visualization

The HTML-based visualization creates a data layer for each of the 22 logical interface categories; See Fig. 6. Users select the interface layers of interest on the list of 22 interface layers. The selected layers are displayed stacked from the straight-on perspective. The user sees the selected overlapping actors and their interfaces. The data layers can easily be toggled on and off with a mouse click making commonalities

Fig. 5 Logical Interface Category 6, Interface between controls in different organizations [1]

Fig. 4 Stacked Logical Interface Categories [1]

and differences easy to identify. The web page’s stacked depiction focuses the user’s effort on the data without the tedium of thumbing through 50 pages in the document.

The web page visualization proved to be a good first step. However, from the outset, we know that it would sacrifice some information in the NISTIR’s Logical Interface Category diagrams not easily captured with this approach. For example to see more detail about the interface between two actors, a user would still refer back to the paper document. The absence of the third dimension in the visualization made it difficult for the user to track which actors and interfaces were associated with each interface layer. B. MATLAB Visualization

Our efforts to create the 3D representation using MATLAB were much more complex. The actors and interfaces for each logical interface category are assigned coordinates in the x-y plane. The logical interface categories are assigned coordinates on the z axis; see Fig. 3. Like the HTML model, interface categories of interest can be selected and stacked to focus upon the logical interface layers of interest. An attractive feature of the MATLAB representation is the graphical representation can be rotated in the three axes to gain the best view of the relationships of interest. The biggest feature this model has is the unique ability to rotate the model and visualize it from every angle.

Fig. 7 shows the top layer of the visualization model as represented in MATLAB, the actors portrayed are in the similar locations and color coded to the NISTIR 7628 layouts to minimize confusion as much as possible. The MATLAB

tool allows a unique element to be added to model, which is a three dimensional layer that allows users to see the depth of the NISTIR 7628, something that has never been modeled before.

As well as the depth included in the MATLAB model, the information about each connection and relationship can be stored in the tool and accessed with a simple click of the button. This will allow people to understand and grasp a much larger amount of information with the simplicity of an application. Lacking in the MATLAB model is the clarity within a few aspects. Labeling the current model proved to be quite challenging. We found labels that work from a straight-on perspective can be quite difficult to read from other vantage points and create clutter that obscures important details.

We have presented the tool at several conference events with industry, government, and academic participants – and received very encouraging feedback. C. NetAPT Visualization

NISTIR 7628 provided a conceptual construct for understanding the actors and their interaction. However, the NISTIR 7628 paradigm can provide misleading impressions about the physical implementations of the power grid’s cyber systems. The Network Access Policy Tool (NetAPT) developed at the Information Trust Institute; University of Illinois at Urbana-Champaign provided a contracting graphical view of the actors and their interfaces. NetAPT ingests firewall rule information and uses it to generate a

Fig. 6 HTML Model

graphical depiction – a depiction based upon actual system connections and less upon the conceptual functions captured in NISTIR 7628. Fig. 8 provided an example of a prototype power providers system. Now, this depiction has a much different structure than the NISTIR 7628 paradigm would produce. Both representations are valid. This poses interesting lines of investigation leveraging one representation against the other to gain insights that might otherwise not be apparent.

IV. FUTURE EFFORTS While our efforts to date have produced interesting and

useful representations, we recognize that our progress is far from our envisioned functionality. Through our work to-date, we have gained an appreciation for the significant challenges involved.

In the near term, we are seeking off-the-shelf applications that can be adapted to our purposes. Immediate objectives include current and the following desired capabilities to

Label graphical features and easily accommodate interactive perspective changes

Easily zoom-in and pan-out

Increase available information content, while affording the user robust displayed content control

Automatically generate graphic layouts that are both useful and appealing form alternate perspectives

Automatically ingest data to minimize the level of effort required to create, organize, and maintain the underlying “data stores”

A. Conclusions With daily reports of attacks, there is an urgent need to

broadly improve the power grids cyber security posture. The diversity and complexity of the measures environment. Consequently, it is very important that the efforts be placed against the most dangerous threat and vulnerability combinations. This drives the urgent need to understand the requirements established in documents like NISTIR 7628, which are extremely complex. We have demonstrated first steps to producing a graphical depiction that aids synthesizing key insights into the requirements. We have also refined our vision for an application to aid synthesizing complex cyber security information.

REFERENCES [1] NISTIR 7628: Guidelines to Smart Grid Cyber Security, NISTIR 7628,

2010. [2] NetAPT Access Policy Tool. Web. Available:

https://www.perform.illinois.edu/netapt/

Fig. 7 MATLAB Model

Fig. 8 TCIPG NetAPT Cyber Network Representation of Utility [2]

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/ Billi

ng /

Util

ity

Bac

k O

ffice

)

29

NIS

TIR

762

8 G

uide

lines

for S

mar

t Grid

Cyb

er S

ecur

ity v

1.0

– A

ug 2

010

2.3.

1Lo

gica

l Int

erfa

ce C

ateg

orie

s 1—

4

Logi

cal I

nter

face

Cat

egor

y 1:

Inte

rfac

e be

twee

n co

ntro

l sys

tem

s an

d eq

uipm

ent w

ith h

igh

avai

labi

lity,

and

with

com

pute

and

/or b

andw

idth

con

stra

ints

Logi

cal I

nter

face

Cat

egor

y 2:

Inte

rfac

e be

twee

n co

ntro

l sys

tem

s an

d eq

uipm

ent w

ithou

t hi

gh a

vaila

bilit

y, b

ut w

ith c

ompu

te a

nd/o

r ban

dwid

th c

onst

rain

ts

Logi

cal I

nter

face

Cat

egor

y 3:

Inte

rfac

e be

twee

n co

ntro

l sys

tem

s an

d eq

uipm

ent w

ith h

igh

avai

labi

lity,

with

out c

ompu

te o

r ban

dwid

th c

onst

rain

ts

Logi

cal I

nter

face

Cat

egor

y 4:

Inte

rfac

e be

twee

n co

ntro

l sys

tem

s an

d eq

uipm

ent w

ithou

t hi

gh a

vaila

bilit

y, w

ithou

t com

pute

or b

andw

idth

con

stra

ints

Logi

cal i

nter

face

cat

egor

ies 1

thro

ugh

4 co

ver c

omm

unic

atio

ns b

etw

een

cont

rol s

yste

ms

(typi

cally

cen

traliz

ed a

pplic

atio

ns su

ch a

s a S

CA

DA

mas

ter s

tatio

n) a

nd e

quip

men

t as w

ell a

s co

mm

unic

atio

ns b

etw

een

equi

pmen

t. Th

e eq

uipm

ent i

s cat

egor

ized

with

or w

ithou

t hig

h av

aila

bilit

y. T

he in

terf

ace

com

mun

icat

ion

chan

nel i

s cat

egor

ized

with

or w

ithou

t com

puta

tiona

l an

d/or

ban

dwid

th c

onst

rain

ts. A

ll ac

tiviti

es in

volv

ed w

ith lo

gica

l int

erfa

ce c

ateg

orie

s 1 th

roug

h 4

are

typi

cally

mac

hine

-to-m

achi

ne a

ctio

ns. F

urth

erm

ore,

com

mun

icat

ion

mod

es a

nd ty

pes a

re

sim

ilar b

etw

een

logi

cal i

nter

face

cat

egor

ies 1

thro

ugh

4 an

d ar

e de

fined

as f

ollo

ws:

Inte

rfac

e D

ata

Com

mun

icat

ion

Mod

e

–N

ear R

eal-T

ime

Freq

uenc

y M

onito

ring

Mod

e (m

s, su

bcyc

le b

ased

on

a 60

Hz

syst

em) (

may

or m

ay n

ot in

clud

e co

ntro

l act

ion

com

mun

icat

ion)

–H

igh

Freq

uenc

y M

onito

ring

Mod

e (2

s 6

0 s s

can

rate

s)

–Lo

w F

requ

ency

Mon

itorin

g M

ode

(sca

n/up

date

rate

s in

exce

ss o

f 1 m

in, f

ile

trans

fers

)

Inte

rfac

e D

ata

Com

mun

icat

ion

Type

–M

onito

ring

and

Con

trol D

ata

for r

eal-t

ime

cont

rol s

yste

m e

nviro

nmen

t (ty

pica

l m

easu

rem

ent a

nd c

ontro

l poi

nts)

–Eq

uipm

ent M

aint

enan

ce a

nd A

naly

sis (

num

erou

s mea

sure

men

ts o

n fie

ld e

quip

men

t th

at is

typi

cally

use

d fo

r pre

vent

ive

mai

nten

ance

and

pos

t ana

lysi

s)

–Eq

uipm

ent M

anag

emen

t Cha

nnel

(rem

ote

mai

nten

ance

of e

quip

men

t)

The

char

acte

ristic

s tha

t var

y be

twee

n an

d di

stin

guis

h ea

ch lo

gica

l int

erfa

ce c

ateg

ory

are

the

avai

labi

lity

requ

irem

ents

for t

he in

terf

ace

and

the

com

puta

tiona

l/com

mun

icat

ions

con

stra

ints

for

the

inte

rfac

e as

follo

ws:

Ava

ilabi

lity

Req

uire

men

ts –

Ava

ilabi

lity

requ

irem

ents

will

var

y be

twee

n th

ese

inte

rfac

es

and

are

driv

en p

rimar

ily b

y th

e po

wer

syst

em a

pplic

atio

n w

hich

the

inte

rfac

e su

ppor

ts

and

not b

y th

e in

terf

ace

itsel

f. Fo

r exa

mpl

e, a

SC

AD

A in

terf

ace

to a

subs

tatio

n or

pol

e-to

p R

TU m

ay h

ave

a H

IGH

ava

ilabi

lity

requ

irem

ent i

n on

e ca

se b

ecau

se it

is su

ppor

ting

criti

cal m

onito

ring

and

switc

hing

func

tions

or a

MO

DER

ATE

to L

OW

ava

ilabi

lity

if su

ppor

ting

an a

sset

-mon

itorin

g ap

plic

atio

n.

30