wireless sensor systems: security implications for the industrial environment

Wireless Sensor Systems: Security Implications for the

Industrial Environment

Dr. Peter L. FuhrChief Scientist

RAE Systems, Sunnyvale, CA

[email protected]

2ISA Wireless Security, P. Fuhr

RAE Systems Inc.• Pervasive Sensing Company

based in Silicon Valley founded in 1991

Capabilities– Radiation detection

• Gamma and neutron– Chemical/vapor detection

• Toxic gas, VOC, combustible gas, oxygen, CWA, temperature, humidity, C02

– Redeployable sensor networks– Mobile and fixed wireless

monitors– Cargo Container Sensor Systems

Dr. Peter Fuhr, Presenter: 480+ publications&presentations in wireless sensornetworking arena. Old-timer in this area…etc etc.


ContributorsA number of individuals have provided “content” for these slides. They include:

Wayne Manges, Oak Ridge National LaboratoryRobert Poor, EmberPat Gonia, HoneywellHesh Kagan, Foxboro/InvensysKang Lee, NISTTom Kevan, AdvanstarRamesh Shankar, Electric Power Research InstituteLarry Hill, Larry Hill ConsultingRob Conant, DustRick Kriss, XsilogyGideon Varga, Dept of EnergyJack Eisenhauser, EnergeticsMichael Brambley, Pacific Northwest National LabsDavid Wagner, UC-Berkeley

Undoubtedly, there are other contributors too (apologies if your name is not listed).


Wireless Sensor Networking…it’s not cellular telephony

…it’s not just WiFi...(and it just may be the next big thing)

Each dot represents one cell phone tower.

Wireless devices circa 1930


Sensor Market: $11B in 2001Installation (wiring) costs: >$100B

Freedonia Group report on Sensors, April 2002

• Fragmented market platform opportunity

• Installation cost limits penetration

reducing installation cost increases market size

Slide courtesy of Rob Conant, Dust

Highly FragmentedSensor Market


Industrial Market SizingSensor Networking Products

• North American Market for Wireless products used in Applications where transmission distances are 1 mile or less:

– 2002 Total: $107 million

– 2006 Forecast: $713 million

– 2010 Estimates: $ 2.1 billion

• Largest Application areas:– 2002: Tank Level Monitoring, Asset Tracking, Preventative

Maintenance

– 2006: Tank Level Monitoring, Preventative Maintenance, Environmental Monitoring

• Conclusions:– Rapid Growth in Industrial markets

– Tank Level Monitoring will remain a significant opportunity

– Key ‘ User’ Needs:• Lower Costs over Wired (or Manual) Solutions• Education of Potential Customers on the Technology• Demonstration of Operational Reliability & Application ‘ Domain’

Knowledge

Slide courtesy of Rick Kriss, Xsilogy


The True cost per monitored node – to the End User

3-YrTOC $$

$

Radio RF Range (dB)

Lower

Higher

InstallationCosts

Higher

Lower

DENSEBluetooth,

802.15.4, WiFi etc

SPARSE1xRTT, FLEX

SAT, etc

Meters Miles$$$$$$

Design For Here

Slide courtesy of Rick Kriss, Xsilogy


What to do with the data?

Great! But how do you get the output signal from the sensor to the location where the information will be interpreted (used)?

Sensor Modifier Output Transducer

PowerSupply

Parameterof Interest

Measurement System Output Signal

Chemical Electrical Mechanical Thermal Radiation Optical Magnetic

Chemical Electrical Mechanical Thermal Radiation Optical Magnetic

Traditionally the output of the sensor was hardwired to some form of interpretive device (e.g., PLC) perhaps relying on a 4-20mA signal…


Outline:

1. Security? Who needs it?2. How is security achieved in a wired channel?3. The Situation for Wireless (its RF in an industrial setting. Spectrum, modulation, encryption, spatial…)

4. Security within various Wireless Delivery Schemes(cellular, WiFi, 802.15.4, Bluetooth, others…)

5. An Integrated Solution6. The Big Review


Oh, who needs security in a wireless channel anyway!

(pretty ridiculous statement isn’t it!


Let’s ask some experts: WINA meeting, Coral Gables, Sept. 2003

www.wireless4industrial.org


What’s a WINA?

In the spring of 2003, the Wireless Industrial Networking Alliance (WINA) was formed to promote the adoption of wireless networking technologies and practices that will help increase industrial productivity and efficiency.

WINA will be holding a 1.5 day meeting at ISA-HQ in RTP, NC on Feb 11/12 – right after the ISA Wireless Security Expo and conference. Check out www.wireless4industrial.org for WINA meeting details AND www.isa.org/wireless for the ISA Wireless Security conf details!


Back to the Question:

Who needs security in a wireless channel anyway!


Strategy Workshop Participants• Suppliers (13)

• System integrators (6)

• Industrial end users (10)

– Chemicals

– Petroleum

– Automotive

• Industry analysts/venture capitalists (3)

• Others (associations, government, media, researchers)

– Energy/Utilities

– Forest Products

– Electronics


End-User View of Industrial WirelessLikes

• Mobility

• Compactness

• Flexibility

• Low cost

• Capability to monitor rotating equipment

• Short range (security)

• Ease of installation

• High reliability

• Impetus to enhance electronics support

Dislikes• Change to status quo• Complexity• High cost for coverage in large

plants• Security issues• Portability issues (power)• Unproven reliability• Too risky for process control• Lack of experience in

troubleshooting (staff)• Restricted infrastructure flexibility

once implemented• Lack of analysis tools


Technology Group: Key Issues

• Security– Jamming, hacking, and eavesdropping

• Power• Value (clear to customer)• Interoperability

– Co-existence with other facility networks, sensors, collectors, technology

• True engineered solution (sensors, collectors, etc.)• Assured performance & reliability/MTBA*• Software infrastructure, data, & systems management• Robustness (at least as good as wired)• RF characterization (radios, receivers, environments)

*mean time between attention


Technology Group: Criticality Varies by Application (5 = most critical)

Attributes Monitor Control Alarm Shutdown

BizWLAN

Latency 2-3 3-5 5 5 1

Device Reliability 2-3 3-5 5 5 1

Raw Thru-put (node / aggr.)

2 / 5 2.5 /2.5 1 / 4 1 / 1 1/5

Scalability (Max.# nodes)

5 4 4 1 2-3

Data Reliability 1 5 5 5 2

Security 1-5 5 5 5 5

Low Cost 5 2 1-3 1 2-3

Gateway Technology 5 1 3-4 1 1

Engineered Solution 1 5 4 5 3

Applications


Industrial CyberSecurity

• The Case of Vitek Boden


• On October 31, 2001 Vitek Boden was convicted of:– 26 counts of willfully using a restricted computer to

cause damage– 1 count of causing serious environment harm

• The facts of the case:– Vitek worked for the contractor involved in the

installation of Maroochy Shire sewage treatment plant.

– Vitek left the contractor in December 1999 and approached the shire for employment. He was refused.

– Between Jan 2000 and Apr 2000 the sewage system experienced 47 unexplainable faults, causing millions of liters of sewage to be spilled.


How did he do it?

• On April 23, 2000 Vitek was arrested with stolen radio equipment, controller programming software on a laptop and a fully operational controller.

• Vitek is now in jail…

Disgruntled Contractor

PLC PLC

Sewage Plant

Rogue Radio


A Favorite 2.4 GHz Antenna


WarDriving – 802.11 HotSpots in Silicon Valley


WarDriving – 802.11 HotSpots in San Francisco


The Question:Who needs security in a wireless channel anyway!

The Answer:

We do. So…How do you provide the appropriate level of security within the acceptable price and “inconvenience” margin -> Risk Management!


Inside vs. Outside?

• Where do attacks come from?

0

10

20

30

40

50

60

70

80

90

Foreign Gov. ForeignCorp.

Hackers U.S.Competitors

DisgruntledEmployees

2002

2001

2000

1999

1998

*Source: “2002 CSI/FBI Computer Crime and Security Survey” Computer Security Institute - www.gocsi.com/losses.

% of R

espondents


An “Outside” Example. When? April 2001


•In the Spring of 2001, the US got it’s first a taste of a new form of warfare. •Launched from overseas and targeted at US critical infrastructure.

“Hacker War I”


•Chinese Hacker Group working to advance and in some cases impose it’s political agenda•During the spring of 2001, Honker Union worked with other groups such as the Chinese Red Guest Network Security Technology Alliance

Honker Union

•Hackers were encouraged to "...make use of their skills for China..." Wired.com

Denial of Service Attacks•Website Defacement•E-mailing viruses to US Government Employees •“KillUSA” package

Attack Methods:


Cyberwar• Cyber attacks and web defacements

increased dramatically after the start of the war against Iraq.

• More than 1,000 sites were hacked in the first 48 hours of the conflict, with many of the attacks containing anti-war slogans.

• Security consultants state that the war against Iraq made March the worst month for digital attacks since records began in 1995.


• North Korea's Mirim College, is a military academy specializing in electronic warfare

• 100 potential cybersoldiers graduate every year

Hacker School


The Question:Who needs security in a wireless channel anyway?

The Answer:

Everyone.


Outline:





Layered Communications

A few details…


Wired Data Security - Encryption

The “traditional” method involved encrypting the data prior to transmission over a potentially insecure channel. The level of protection rests on the encryption algorithm. (There are a few other factors…such as the physical media.)

Slide courtesy of Wayne Manges, ORNL


Outline:

1. Security? Who needs it?2. How is security achieved in a wired channel?3. The Situation for Wireless 4. Security within various Wireless Delivery Schemes(cellular, WiFi, 802.15.4, Bluetooth, others…)



Wireless Buildings

Key to success: reduced installation costs

From many perspectives, THIS is what a wireless sensor network can provide.

Slide courtesy of Pat Gonia, Honeywell


E(t) = A(t) cos[t + (t)]

Modulation

Amplitude Modulation (AM) info is in A(t) Frequency Modulation (FM) info is in Phase Modulation (PM) info is in (t)

Phase = 0o

Phase = 180o

Phase = 270o

Phase = 360o (or back to 0o)

Different vendors use different schemes - and they are not interoperable.


The FCC Frequency Assignment

Different vendors may use different frequencies within the various ISM bands (green in the diagram).

The ISM bands most commonly used are at 433, 915 and 2400 MHz.


Multiple Sensors Sharing the Medium: Multiplexing. FDMA, TDMA and CDMA


Binary Signaling Formats

• Used to Improve Digital Signal Reception and Decision

• NRZ: Non-Return to Zero• RZ: Return to Zero• Unipolar: Only one side of

0V• Bipolar: Both sides of 0V• Manchester: Bi-Phase (“0”

in left 1/2 time slot, “1” in right)


Narrowband or Spread Spectrum?Narrowband uses a fixed carrier frequency, F0.

The receiver then locks onto the carrier frequency, F0.

Easy to implement (inexpensive).Prone to jamming or interference (two transmitters at the

same carrier frequency, F0.Least secure modulation scheme.


Narrowband or Spread Spectrum (cont.) ?Frequency Hopping Spread Spectrum. Uses a carrier

frequency that varies with time, F0(t).

The receiver must track the time-varying carrier frequency, F0(t).

Relatively easy to implement (inexpensive).Prone to jamming or interference (two transmitters at the same carrier

frequency, F0) during any single transmit interval. Hopping rates may be ~1600 hops/second (ala Bluetooth).

Very secure modulation scheme (used in military for decades).

Invented and patented by actress HeddyLamarr and her pianist George Antheil.


Narrowband or Spread Spectrum (cont.) ?

Direct Sequence Spread Spectrum uses a fixed carrier frequency, F0 but interleaves the data with a precise mathematical 0/1 data sequence. (This increases the length of the transmitted information vector making it longer). The information is replicated many times throughout the bandwidth, so if one “lobe” of the information is jammed, the remainder “gets through”. Highly robust technique.

The receiver then locks onto the carrier frequency, F0 receives the signal and then must “undo” the interleaving.

More difficult to implement (more expensive).Most complicated scheme (of these presented).Most secure modulation scheme.


Data

PN Clock

Data

DataClock

Carrier

±1

Local PN ClockLocal

Carrier

±1

±1

Frequency

PowerSpectralDensity

fc Frequency


fc Frequency


fc

DIRECT-SEQUENCE SPREAD-SPECTRUM SIGNALS

Narrow spectrum at output of modulator before spreading

Spectrum has wider bandwidth and lower power density after spreading with PN sequence (PN Rate >> Data Rate)

Original narrowband, high power density spectrum is restored if local PN sequence is same as and lined up with received PN sequence

RFI“Spread”

RFI

PhaseDemod

NarrowBP Filter

WideBP Filter

PN Sequence Generator

PN Sequence Generator


Narrowband or Spread Spectrum (cont.) ?

Which is best?

Each has its pluses and minuses…and each scheme has its share of die-hard advocates and/or naysayers!

From a security standpoint, DSSS is best.

Different vendors use these (and other) schemes at different frequencies within the various ISM bands.


Reality

DSSS FHSS


No Matter What…Its Just an Electromagnetic Field

A(t): amplitude of the wave

: radian frequency of the wave

(t): phase of the wave

E(t) = A(t) cos[t + (t)]


The RF “Footprint”Network “Size”

Personal Area Network: typical radiated power: 0 dBm, size: 10m

Local Area Network: typical radiated power: 20 dBm, size: 100m

Wide Area Network: typical radiated power: >30 dBm, size: >2000m


Network Topologies?

Bus Network

Tree Network

Star Network

Ring Network

Ad Hoc Network

There are SO many technical questions: such as…


The Real World Presents the Wireless Channel with Multipath and Attenuation…and…


Multipath

The Cause

The Effect

Real World:


Atmospheric Attenuation at 2.4 GHzReal World:

Rayleigh Fading @ 2.4GHz


Signal Attenuation at 2.4 GHzReal World:


And Signal-to-Noise Ratios really do matter!

Real World:

Anecdotal Evidence: As Frankfurt has increased the deployment of 2.4 GHz wireless surveillance cameras, the background Noise level has increased by 12 dB. (This plays havoc with the BER or for fixed BER, the overall data rate,)


Which Frequency is Best?Which Frequency is Best?

Notice that the operation at 2.45 GHz is WORSE than at 900MHz (which is worse than 433 MHz).

ALERT! ALERT!!

Real World:


Outline:





Wireless networks use a variety of techniques to enhance security, such as spreading and interleaving. These techniques can make the signal virtually undetectable without prior knowledge about the network. This can improve the security of the network by orders of magnitude.

Wireless Data Security: Encryption, Spreading, Interleaving

Slide courtesy of Wayne Manges, ORNL


The Wireless MarketS

HO

RT

<

R

AN

GE

>

L

ON

G

LOW < DATA RATE > HIGH

PAN

LAN

TEXT GRAPHICS INTERNET HI-FI AUDIO

STREAMINGVIDEO

DIGITALVIDEO

MULTI-CHANNELVIDEO

Bluetooth1

Bluetooth 2

ZigBee

802.11b

802.11a/HL2 & 802.11g


Bluetooth vs. the Rest (cont’d)

802.112.4 GHz, DSSS11 chips/bit11Mbps+20 dBm50m128 devicesCSMA/CAOptional WEPOptional

HomeRF2.4GHz, FHSS50 hops/s1 Mbps+20 dBm50m128 devicesCSMA/CAOptionalOptional

Bluetooth2.4 GHz, FHSS1000+hops/s1Mbps0, +20dBm1-10m, 50m8 devices, PiconetEncryptionYes

ParameterTechnology

Data RatePowerRangeTopology

SecurityVoice Channel

ZigBee (proposed)2.4 GHz,DSSS15 chips/bit40 kbits/s0dBm100m100s devices, CSMA/CANot yetNo

Bluetooth – aka IEEE 802.15.1

ZigBee – aka IEEE 802.15.4


Side by Side


802.11?


The Worldwide View of the 802.11 Spectral Space


Radiated Field from a single AP (Kansas City)


20dB Attenuation Profile for Univ of Kansas Eng Bldg., Mesh and AP deployments


WEP

• The industry’s solution: WEP (Wired Equivalent Privacy)

– Share a single cryptographic key among all devices

– Encrypt all packets sent over the air, using the shared key

– Use a checksum to prevent injection of spoofed packets

(encrypted traffic)


Early History of WEP

802.11 WEP standard released1997

Simon, Aboba, Moore: some weaknessesMar 2000

Walker: Unsafe at any key sizeOct 2000

Borisov, Goldberg, Wagner: 7 serious attacks on WEP

Jan 30, 2001

NY Times, WSJ break the storyFeb 5, 2001


Subsequent Events

Jan 2001Borisov, Goldberg, Wagner

Arbaugh: Your 802.11 network has no clothes

Mar 2001

Arbaugh, Mishra: still more attacksFeb 2002

Arbaugh: more attacks …May 2001

Newsham: dictionary attacks on WEP keysJun 2001

Fluhrer, Mantin, Shamir: efficient attack on way WEP uses RC4Aug 2001


WEP Attack Tools

• Downloadable procedures from the Internet– To crack the Key:

• AirSnort– http://airsnort.sourceforge.net

• WEPCrack– http://sourceforge.net/projects/wepcrack/

– To brute force enter into WLAN, • THC-RUT

– http://www.thehackerschoice.com/releases.php


Wi-Fi Protected Access (WPA)

– Flaws in WEP known since January 2001 - flaws include weak encryption, (keys no longer than 40 bits), static encryption keys, lack of key distribution method.

– IEEE developing 802.11i standard for enhanced wireless security - Addresses weak data encryption and user authentication within existing 802.11 standard.

– 802.11i standard will not be ratified until late 2003, possibly early

2004 - outstanding issues.

– WPA standard joint effort between Wi-Fi Alliance and IEEE - WPA a subset of IEEE 802.11i standard (Draft 3.0).

•WPA provides stronger data encryption (weak in WEP) and user authentication (largely missing in WEP).


WPA – Data Encryption– WPA uses Temporal Key Integrity Protocol (TKIP) - stronger data encryption, addresses

known vulnerabilities in WEP.

•TKIP chosen as primary encryption cipher suite - Easily deployed and supported in legacy 802.11b hardware compared to other available cipher suites.

– TKIP based on RC4 stream cipher algorithm, surrounds WEP cipher engine with 4 new algorithms,

1. Extended 48-bit Initialization Vector (IV) and IV sequencing rules (compared to the shorter 24-bit WEP RC4 key).

2. New per-packet key mixing function.

3. Derivation and distribution method - a.k.a. re-keying.

4. A message integrity check (MIC) - a.k.a. ‘Michael’, ensures messages haven’t been tampered with during transmission.


WPA – Data Encryption, cont’d• the Temporal Key Integrity Protocol.

•DA – Destination Address TKIP – Temporal Key Integrity Protocol •ICV– Integrity Check Value TSC – TKIP Sequence Counter •MPDU – Message Protocol Data Unit TTAK– result of phase 1 key mixing of Temporal Key •MSDU – MAC Service Data Unit and Transmitter Address •RSN – Robust Security Network WEP – Wired Equivalent Privacy •SA – Source Address WEP IV – Wired Equivalent Privacy Initialization Vector •TA – Transmitter Address

MIC Key

TSC

SA + DA + Plaintext MSDU

Data

Ciphertext MPDU(s)

WEP Encapsulation

MIC

TTAK Key

Plaintext MSDU +

MIC Fragment(s)

Phase 2 key mixing

Plaintext MPDU(s)

WEP seed(s) (represented as WEP IV + RC4

key)

Phase 1 key mixing

TA

Temporal Key


WPA – Data Encryption, cont’d– TKIP implements countermeasures - reduces rate which attacker can

make message forgery attempts down to two packets every 60 seconds.

– After 60 second timeout new PMK or Groupwise Key generated, depending on which attacked – ensures attacker cannot obtain information from attacked key.

– Countermeasures bound probability of successful forgery and amount of information attacker can learn about a key.

– TKIP is made available as firmware or software upgrade to existing legacy hardware.

•TKIP eliminates having to replace existing hardware or having to purchase new hardware.


Bluetooth?


BlueTooth- Some Specifications

• Uses unlicensed 2.402 - 2.480 GHz frequency range• Frequency hopping spread spectrum 79 hops

separated by 1 MHz• Maximum frequency hopping rate: 1600 hops/sec• Nominal range: 10 cm to 10 meters• Nominal antenna power: 0 dBm• One complete Bluetooth data packet can be

transmitted within each 625 msec hop slot.


Potential Bluetooth Markets


Bluetooth Market Forecast

Nov’03: 100M Bluetooth compliant devices worldwide


Bluetooth Protocol Stack• Adopted Protocols

– PPP(Point-To-Point Protocol)– TCP/UDP/IP– OBEX-Session Protocol for IrDA(Infrared Data

Association)– Contents Fromat(e.g. vCard, vCalendar)– WAP-Wireless Application Protocol


Bluetooth Security

• Supports Unidirectional or Mutual Encryption based on a Secret Link key Shared Between Two Devices

• Security Defined In 3 modes:– Mode1- No Security– Mode 2 - Service Level Security: Not Established

Before Channel is Established at L2CAP– Mode 3 - Link Level Security: Device Initiates

Security Before LMP Link is Setup• Devices and Services can be Set for Different Levels of Security

– Two Trust Levels are Set for Devices• Trusted Device: Fixed Relationship and Unrestricted

Access to All Services• Untrusted: No Permanent relationship and Restricted

Services


Bluetooth Security

• Devices and Services can be Set for Different Levels of Security– Two Trust Levels are Set for Devices

• Trusted Device: Fixed Relationship and Unrestricted Access to All Services

• Untrusted: No Permanent relationship and Restricted Services


Bluetooth Security• 3 Levels of Service Access

– Require Authorization and Authenication– Require Authentication Only– Default Security for Legacy Applications


But is this Wireless Link Secure?

Newsflash: Jan 2001: Norwegian “hackers” crack a Bluetooth transmissionNewsflash: Jan 2001: Norwegian “hackers” crack a Bluetooth transmission


Analysis of a BlueTooth Transmission

High overhead?


802.15.4/Zigbee?


IEEE 802.15.4 standard

• Includes layers up to and including Link Layer Control– LLC is standardized in 802.1

• Supports multiple network topologies including Star, Cluster Tree and Mesh

IEEE 802.15.4 MAC

IEEE 802.15.4 LLC IEEE 802.2LLC, Type I

IEEE 802.15.42400 MHz PHY

IEEE 802.15.4868/915 MHz PHY

Data Link Controller (DLC)

Networking App Layer (NWK)

ZigBee Application Framework

• Features of the MAC: Association/dissociation, ACK, frame delivery, channel access mechanism, frame validation, guaranteed time slot management, beacon management, channel scan• Low complexity: 26 primitives

versus 131 primitives for 802.15.1 (Bluetooth)


PHY overview• Speed

– 20, 40 or 250 kbps

• Channels

– 1 channel in the 868MHz band

– 10 channels in the 915MHz band

– 16 channels in the 2.4GHz band

• Modulation

– BPSK (868MHz/20kbs)

– BPSK (915MHz/40kbps)

– O-QPSK (2.4GHz/250kbps)

• Coexistence w/

– 802.11b DSSS

– 802.15.1 FHSS

– 802.15.3 DSSS


MAC overview• Security support• Power consumption

consideration• Dynamic channel

selection• Network topology

–Star topology

–p2p topology

–cluster-tree network topology


Device classification• Full Function Device (FFD)

– Any topology

– Can talk to RFDs or other FFDs

– Operate in three modes

• PAN coordinator

• Coordinator

• Device.

• Reduced Function Device (RFD)

– Limited to star topology

– Can only talk to an FFD (coordinator)

– Cannot become a coordinator

– Unnecessary to send large amounts of data

– Extremely simple

– Can be implemented using minimal resources and memory capacity


Transmission management• Acknowledgement

–No ACK

–ACK

–Retransmission

–Duplicate detection

• Indirect transmission


Security

• Unsecured mode• ACL mode

–Access control

• Secured mode–Access control

–Data encryption

–Frame integrity

–Sequential freshness


Scalable Security

• Assume the attacker can deploy own nodes (can create a “ring” at some distance from controller)[Wisenet 2003]

• Enemy nodes “mimick” the mesh nodes; they ACK the “health inquiry” as if everything was OK – but they do not forward to the rest of the net

• The rest of the network is virtually cut off from inspection by controller

• Need secure key and a random seed that changes at each round


What About:

1451.5?1xRTT?

SAT?CDPD?

Others?

No time this morning!


Outline:





Integrated Industrial Networks?There are SO many technical questions: such as…

If the sensor network is to integrate into an industrial setting, then youshould be cognizant of the Industrial Networking arena.


Industrial Device Network Topology

• Typically, three layers of networking make up enterprisewide networks. Ethernet acts as the company's intranet backbone, and it's linked to controllers or industrial PCs, which supply strategic data to the enterprise. An industrial network, or fieldbus, links sensors and smart devices. A gateway (not uncommon in a large system with lots of devices) links devices that have only RS-232 or RS-485 ports to the fieldbus system.


Industrial Device Networks• General characteristics for industrial device

networks have arisen.

• Obviously the complexity of the network increases as the functionality is increased.


Classification of Industrial Networks

• Three logical groupings of instrumentation networks used in an industrial setting.

• There are over 100 different proprietary networks in the field.


Inside Security Incident

• Employee attacks PLC in another plant area over PLC highway.

• Password changed to obscenity, blocking legitimate maintenance and forcing process shutdown.

* Source: BCIT Industrial Security Incident Database (ISID)

Disgruntled Employee

PLC PLC PLCPLC

Steam Plant Paper Plant

Plant Highway


Network Positioning-

F

un

cti

on

alit

y

+

Ethernet TCP/IP

- Cost +

+ C

om

ple

xity -

- Data +

DeviceNetOther CANSDS

Fieldbus H1Profibus-PAModbusHART

Profibus-DPInterbus-SRemote I/O

Profibus-FMSData Highway+Modbus Plus

ASi, Seriplex, Hardwiring, RS485 etc.

ControlNetFoundation Fieldbus H2


Too Focused on Internet Issues?

• Myth #1: Our SCADA/PLC/DCS is safe if we don’t connect to the Internet.

• Myth #2: Our Internet firewall will protect our control systems.

• Myth #3: Our IT department understands process control issues and security.


Is Industrial Comm Security Too Focused on Internet Issues?

Field Devices

Control Network

SCADA Programming Stations

PLC PLC

RemoteEngineering

Production Planning

Manufacturing Logistics

Enterprise Resource Planning

ProcessHistorian

Enterprise Network

Internet

Firewall

Ethernet

Production Networks

)))))

HandheldOperatorTerminal

Modem

OEM

802.11 WLAN

Source (used by permission): Interface Technologies, Windsor, CT, 2002

WarDialing Attack


Outline:





Bit Rate vs. Quality of Service

How Many

Bits are

Needed?

The more bits you xmit, the more power you consume!


Coding vs. Quality of Service

Is Coding

Really

Necessary?


Direct Sequence Spread Spectrum


Comparing Wireless

Tech. Range RF Power

Battery life

Numbers In Area

DSSS Medium Low longest High

FHSS Long High Short Medium

UWB Medium Lowest short High

Narrow band

Longest highest short Lowest


Technology Beats Marketing in Performance!

Technology versus AttributesSummary Chart

Technology

Attribute

DSSSFHSSUWB

CDMATDMAFDMA

LowPowerDesigns

MobileAd HocNetworks

PowerHarvesting

EmbeddedIntelligence Diversity FEC

Open Standards

BPSKQPSKM-ary

900MHz2.4GHz5.8GHz

Long Range NA NA NA yes NA NA yes yes NA NA 900MHzPlug-and-Play DSSS CDMA NA NA NA NA NA NA yes NA NALong Battery life FHSS FDMA yes NA yes yes yes yes NA M-ary 900MHzLow RFI risk DSSS NA yes yes NA yes yes NA NA NA 5.8GHzSelf Locating DSSS CDMA NA NA NA yes yes NA NA NA 5.8GHzSecure UWB CDMA yes NA NA yes yes NA NA NA 5.8GHzHigh throughput UWB NA NA NA NA yes yes yes NA M-ary 5.8GHznon line-of-sight UWB NA NA yes NA NA yes NA NA NA 900MHzrobust connections DSSS CDMA NA yes NA NA yes yes NA BPSK 5.8GHzlow cost FHSS FDMA yes NA NA NA NA NA yes BPSK 900MHzsmall size FHSS TDMA yes NA NA NA NA NA NA BPSK 5.8GHz


Statistics on Types of Attacks

0 20 40 60 80 100 120

Theft of Propriety Info

Sabotage

Telecom Evesdropping

System Penetration

Insider Abuse of Net Access

Finacial Fraud

Virus

Unauthorized Insider Access

Telecom Fraud

Active Wiretap

Laptop Theft

Denial of Service

1997

1998

1999

2000

2001

2002

*Source: “2002 CSI/FBI Computer Crime and Security Survey” Computer Security Institute - www.gocsi.com/losses.

% of Respondents


Optimization of Security vs. Cost• Risk reduction is balanced against the cost of

security counter measures to mitigate the risk.

Security Level

Cost ($)

Cost of SecurityCountermeasures

Cost of SecurityBreaches

Optimal Level of Securityat Minimum Cost


Risk in Safety vs. Risk in Security

• Safety Definition: “Risk is a measure of human injury, environmental damage, or economic loss in terms of both the incident likelihood and the magnitude of the loss or injury.”

• Security Definition: “Risk is an expression of the likelihood that a defined threat will exploit a specific vulnerability of a particular attractive target or combination of targets to cause a given set of consequences.”

*Source: CSPP Guidelines For Analyzing And Managing The Security Vulnerabilities Of Fixed Chemical Sites


Firewall Architectures

• The external router blocks attempts to use the underlying IP layer to break security (e.g. IP spoofing, source routing, packet fragments, etc) and forces all traffic to the proxy.

• The proxy firewall handles potential security holes in the higher layer protocols.

• The internal router blocks all traffic except to the proxy server.

Internal RouterInternet

External Router


There’s lot of “Wireless”

• From cellphones to PDAs to WiFi to Satellite-based


Wireless LAN Standards


Existing/Developing IEEE 802.11 Standards

• 802.11- • 802.11a – • 802.11b – • 802.11e – • 802.11f – • 802.11g – • 802.11h – • 802.11i – • 802.1x – • 802.15 – • 802.16 –

Frequency Hopping/DSSS 54Mbps / HyperLAN(1999) 11MbpsQuality of ServicePoint 2 Point Roaming(2003) 54Mbps European Inspired Changes(Q2,2004) New Encryption Protocols(Q2,2004) Port Based Network Access Personal Area Network (WPAN)Wireless Metropolitan Area Network (WMAN)


PicoCellBTS

PicoCellBTS

NoiseFloorLifter

6 MCU GSM SERVER

On-Board Network Integration

SDU

Wireless Backbone for Inflight “Entertainment”

…and we haven’t even touched on RFID!


There’s lot of “Wireless”

• And it all needs to feel more Secure!


For a real review of networking security…

• Take Eric Byrnes ISA course IC32C…


Will History Repeat?

analog cellphones: AMPS1980

1990

2000

analog cloning, scannersfraud pervasive & costly

digital: TDMA, GSM

TDMA eavesdropping [Bar]

more TDMA flaws [WSK]GSM cloneable [BGW]GSM eavesdropping [BSW,BGW]

Future: 3rd gen.: 3GPP, …

Cellular networks

802.11, WEP

2001

2002

WEP broken [BGW]WEP badly broken [FMS]

WPA

2000

1999

Future: 802.11i

2003

attacks pervasive

wireless networks

Proprietary systems

2002

1451, 802.15.4, TinyOS

Future: ???

2003

sensor networks

wireless security: not just 802.11


• PATRIOT (Provide Appropriate Tools Required to Intercept and Obstruct Terrorism)

• Legally classifies many hacking attacks as acts of terrorism

PATRIOT Act


So… If Nothing else, at least PLEASE do this for your WiFi

System!

WLAN Security Countermeasures• Conduct site survey

• Identify areas of signal strength and weakness• Do a “walkaround” with NetStumbler• Document and shut down rogue access points• Document and shut down unauthorized wireless NICs• AND TURN ON SOME LEVEL OF THE PROVIDED

PROTECTION!


Oh…

And don’t forget that as you layer in all of these wacky encryption schemes and CDMA and DSSS and…and… that it takes some joules to actually implement this. So if your wireless network has primepower (a.k.a. AC) you’re ok. But if you’re going off a battery then it’s a tradeoff of security versus Power Consumption You Choose that one!


...and in the end...

...or...

Two potential forms of wireless sensor networks.

And they should both be secure!

HoneyBee with RFID

BumbleBee with RF xcvr


Outline:



5. An Integrated Solution6. The Big Review7. Glossary and References


Glossary10BASE-T: IEEE 802.3 standard for a twisted-pair Ethernet network. 10 Mbps transmission rate over baseband using unshielded, twisted-pair cable.

802.11: The IEEE 802.11 standard defines both frequency hopping and direct sequence spread spectrum solutions for use in the 2.4-2.5 MHz ISM (Industrial, Scientific, Medical) band.

802.11a: The Global System for Mobile Communications standard for worldwide wireless communications on wide area networks (WANs).

802.11b: The portion of the 802.11 specification that defines the 11 Mbps data rate.

A

Access Point: Provides a bridge between Ethernet wired LANs and the wireless network. Access points are the connectivity point between Ethernet wired networks and devices (laptops, hand-held computers, point-of-sale terminals) equipped with a wireless LAN adapter card.

Analog phone: Comes from the word "analogous," which means similar to. In telephone transmission, the signal being transmitted from the phone—voice, video or image—is analogous to the original signal.

Antenna-Directional: Transmits and receives radio waves off the front of the antenna. The power behind and to the sides of the antenna is reduced. The coverage area is oval with the antenna at one of the narrow ends. Typical directional antenna beam width angles are from 90° (somewhat directional) to as little as 20°(very directional). A directional antenna directs power to concentrate the coverage pattern in a particular direction. The antenna direction is specified by the angle of the coverage pattern called the beam width.

Antenna-Omni-directional: Transmits and receives radio waves in all directions. The coverage area is circular with the antenna at the center. Omni-directional antennas are also referred to as whip or low-profile antennas.

Association: The process of determining the viability of the wireless connection and establishing a wireless network's root and designated access points. A mobile unit associates with its wireless network as soon as it is powered on or moves into range.

ATM: Asynchronous Transfer Mode. A type of high-speed wide area network.


GlossaryB

Backbone: A network that interconnects other networks, employing high-speed transmission paths and often spanning a large geographic area.

Bandwidth: The range of frequencies, expressed in hertz (Hz), that can pass over a given transmission channel. The bandwidth determines the rate at which information can be transmitted through the circuit.

Bandwidth Management: Functionality that allocates and manages RF traffic by preventing unwanted frames from being processed by the access point.

BC/MC: Broadcast frames; Multicast frames

Beacon: A uniframe system packet broadcast by the AP to keep the network synchronized. A beacon Includes the Net_ID (ESSID), the AP address, the Broadcast destination addresses, a time stamp, a DTIM (Delivery Traffic Indicator Maps) and the TIM (Traffic Indicator Message).

BFA Antenna Connector: Miniature coaxial antenna connector manufactured by MuRata Manufacturing Corporation.

Bluetooth: See Wireless Personal Area Networks.

Bridge: A device that connects two LANs of the same or dissimilar types. It operates at the Data Link Layer, as opposed to routers. The bridge provides fast connection of two collocated LAN segments that appear as one logical network through the bridge.

Buffer: A segment of computer memory used to hold data while it is being processed.


GlossaryC

CAM: Continuously Aware Mode: Mode in which the adapter is instructed to continually check for network activity.

Card and Socket Services: Packages that work with the host computer operating system, enabling the Wireless LAN adapter to interface with host computer configuration and power management functions.

Cellular Phone: Low-powered, duplex, radio/telephone that operates between 800 and 900 MHz, using multiple transceiver sites linked to a central computer for coordination. The sites, or "cells," cover a range of one to six or more miles in each direction.

Centrex: Business telephone service offered by a local telephone company from a local telephone company office. Centrex is basically a single line phone system leased to businesses as a substitute for a business that is buying or leasing its own on-premises phone system or PBX.

CDMA and TDMA: The Code Division Multiple Access and Time Division Multiple Access standard for wireless communications on wide area networks (WANs) in North America.

Circuit switching: The process of setting up and keeping a circuit open between two or more users so that users have exclusive and full use of the circuit until the connection is released.

Client: A computer that accesses the resources of a server.

Client/Server: A network system design in which a processor or computer designated as a server (such as a file server or database server) provides services to other client processors or computers.

CODEC: Coder-Decoder. Audio compression/decompression algorithm that is designed to offer excellent audio performance. Converts voice signals from their analog form to digital signals acceptable to modern digital PBXs and digital transmission systems. It then converts those digital signals back to analog so that you may hear and understand what the other person is saying.

Computer Telephony Integration: Technology that integrates computer intelligence with making, receiving, and managing telephone calls. Computer telephony integrates messaging, real-time connectivity, and transaction processing and information access.


GlossaryD

Data Terminal: Computer transmit and receive equipment, including a wide variety of dumb terminals or terminals without embedded intelligence in the form of programmed logic. Most data terminals provide a user interface to a more capable host computer, such as a mainframe or midrange computer.

Decryption: Decryption is the decoding and unscrambling of received encrypted data. The same device, host computer or front-end processor, usually performs both encryption and decryption.

Desktop Conferencing: A telecommunications facility or service on a PC that permits callers from several diverse locations to be connected together for a conference call.

Digital Phone System: Proprietary phone system provided by a vendor, such as AT&T, Mitel, Northern Telecom, and so on. The signal being transmitted in a digital phone system is the same as the signal being transmitted in an analog phone system. The system can consist of a proprietary PBX system that converts voice signals from their analog form to digital signals, and then converts those digital signals back to analog. Alternatively, the conversion from analog-to-digital can occur in a digital phone.

Direct Inward Dialing: DID. The ability for a caller outside a company to call an internal extension without having to pass through an operator or attendant. In large PBX systems, the dialed digits are passed from the PSTN to the PBX, which then completes the call.

Direct-Sequence (DS) Spread Spectrum: Direct sequence transmits data by generating a redundant bit pattern for each bit of information sent. Commonly referred to as a "chip" or "chipping code," this bit pattern numbers 10 chips to one per bit of information. Compared with frequency hopping, direct sequence has higher throughput, wider range and is upgradable in the 2.4GHz band.

Diversity Reception: The use of two antennas attached to a single access point to improve radio reception. The second antenna is used only for receiving radio signals, while the primary is used for both transmitting and receiving.

Driver: A program routine that links a peripheral device, such as a mobile unit's radio card, to the computer system.


GlossaryElement-level Management: Level of technologies aimed at small or medium-sized businesses.

Encryption: Entails scrambling and coding information, typically with mathematical formulas called algorithms, before the information is transmitted over a network.

Ethernet: A local area network used for connecting computers, printers, workstations, terminals, servers, and so on, within the same building or campus. Ethernet operates over twisted wire and over coaxial cable at speeds up to 100 Mbps, with 1 Gbps speeds coming soon.

Filtering: Prevents user-defined frames from being processed by the access point.

Fragmentation Threshold: The maximum size for directed data packets transmitted over the radio. Larger frames fragment into several packets this size or smaller before transmission over the radio. The receiving station reassembles the transmitted fragments.

Frame Mode: A communications protocol supported by the OEM Modules. The frame protocol implements asynchronous serial Point-to-Point (PPP) frames similar to those used by serial Internet protocols.

Frequency Hopping (FH) Spread Spectrum: Hedy Lamarr, the actress, is credited in name only for inventing frequency hopping during World War II. As its label suggests, frequency hopping transmits using a narrowband carrier that changes frequency in a given pattern. There are 79 channels in a 2.4GHz ISM band, each channel occupying 1MHz of bandwidth. A minimum hop rate of 2.5 hops per channel per second is required in the United States. Frequency hopping technology is recognized as superior to direct sequence in terms of echo resistance, interference immunity, cost and ease-of-installation. To date, there has also been a greater selection of WLAN products from which to chose.

FTP (File Transfer Protocol): A common Internet protocol used for transferring files from a server to the Internet user. It uses TCP/IP commands.

Gain, dBi: Antenna gain, expressed in decibels referenced to a half wave dipole.

Gain, dBi: Antenna gain, expressed in decibels referenced to a theoretical isotropic radiator.

Gain, dBic: Antenna gain, expressed in decibels referenced to a theoretical isotropic radiator that is circularly polarized.

Gatekeeper: Software that performs two important functions to maintain the robustness of the network: address translation and bandwidth management. Gatekeepers map LAN aliases to IP addresses and provide address lookups when needed.

Gateway: Optional element in an H.323 conference. Gateways bridge H.323 conferences to other networks, communications protocols, and multimedia formats. Gateways are not required if connections to other networks or non-H.323 compliant terminals are not needed.

GHz: International unit for measuring frequency is Hertz (Hz), which is equivalent to the older unit of cycles per second. One Gigahertz (GHz) is one billion Hertz. Microwave ovens typically operate at 2.45 GHz.

GSM: The Global System for Mobile Communications standard for worldwide wireless communications on wide area networks (WANs).


GlossaryH.323: An umbrella standard from the International Telecommunications Union (ITU) that addresses call control, multimedia management, and bandwidth management for point-to-point and multi-point conferences, as well as interfaces between LANs and other networks. The most popular standard currently in use.

Handheld PC (HPC): The term adopted by Microsoft and its supporters to describe handheld computers employing Microsoft's Windows CE operating system.

Interactive Voice Response: System used to access a database access application using a telephone. The voice processing acts as a front-end to appropriate databases that reside on general purpose computers. For instance, DTMF (touch tone) input of a Personal Identification Number can be required for access or more unusual and expensive techniques such as voice recognition and voice print matching.

Internet: World's largest network, often referred to as the Information Superhighway. The Internet is a virtual network based on packet switching technology. The participants on the Internet and its topology change on a daily basis.

Internet Commerce: Electronic business transactions that occur over the Internet. Samples of Internet commerce applications include electronic banking, airline reservation systems, and Internet malls.

Internet Phone: Device used to transmit voice over the Internet, bypassing the traditional PSTN and saving money in the process. An Internet phone can be a small phone (such as the NetVision Phone) or a multimedia PC with a microphone, speaker, and modem.

Interoperability: The ability of equipment or software to operate properly in a mixed environment of hardware and software, from different vendors. Enabled by the IEEE 802.11 open standard.

IP (Internet Protocol): The Internet standard protocol that defines the Internet datagram as the unit of information passed across the Internet. Provides the basis of the Internet connection-less- best-effort packet delivery service. The Internet protocol suite is often referred to as TCP/IP because IP is one of the two fundamental protocols.

International Roaming: Ability to use one adapter worldwide.

Intranet: A private network that uses Internet software and Internet standards. In essence, an intranet is a private Internet reserved for use by people who have been given the authority and passwords necessary to use that network.

ISDN: Integrated Services Digital Network. Emerging network technology offered by local phone companies that is designed for digital communications, computer telephony, and voice processing systems.

ISM Band: ISM bands--instrumental (902-928MHz), science (2.4-2.4835GHz), and medical (5.725-5.850GHz)--are the radio frequency bands allocated by the FCC for unlicensed continuous operations for up to 1W. The most recent band approved by the FCC for WLANs was the medical band in January 1997.

ITU: International Telecommunications Union. Standards body that defined H.323 and other international standards.

Jitter: Noise on a communications line which is based on phase hits, causing potential phase distortions and bit errors..


GlossaryKerberos: A widely deployed security protocol that was developed at the Massachusetts Institute of Technology (MIT) to authenticate users and clients in a wired network environment and to securely distribute encryption keys.

Key Telephone System: A system in which the telephone has multiple buttons permitting the user to directly select central office phone lines and intercom lines. Key phone systems are most often found in relatively small business environments, typically around 50 telephones.

Layer: A protocol that interacts with other protocols as part of an overall transmission system.

LPD (Line Printer Daemon): A TCP-based protocol typically used between a Unix server and a printer driver. Data is received from the network connection and sent out over the serial port.

MAC (Media Access Control): Part of the Data Link Layer, as defined by the IEEE, this sublayer contains protocols for gaining orderly access to cable or wireless media.

MD5 Encryption: An authentication methodology when MU is in foreign subnet.

MIB (Management Information Base): An SNMP structure that describes the specific device being monitored by the remote-monitoring program.

Microcell: A bounded physical space in which a number of wireless devices can communicate. Because it is possible to have overlapping cells as well as isolated cells, the boundaries of the cell are established by some rule or convention.

Modem: Equipment that converts digital signals to analog signals and vice versa. Modems are used to send digital data signals over the analog PSTN.

MMCX Antenna Connector: Miniature coaxial antenna connector in use by several major wireless vendors.

Mobile IP: The ability of the mobile unit to communicate with the other host using only its home IP address, after changing its point of attachment to the Internet and intranet.

Mobile Unit (MU): May be a Symbol Spectrum24 terminal, PC Card and PCI adapter, bar-code scanner, third-party device, and other

Mobile Unit Mode: In this mode, the WLAN adapter connects to an access point (AP) or another WLAN installed system, allowing the device to roam freely between AP cells in the network. Mobile units appear as network nodes to other devices.

Modulation: Any of several techniques for combining user information with a transmitter's carrier signal.

Multipath: The signal variation caused when radio signals take multiple paths from transmitter to receiver.

Multipath Fading: A type of fading caused by signals taking different paths from the transmitter to the receiver and, consequently, interfering with each other.


GlossaryNode: A network junction such as a switch or a routing center.

Packet Switching: Refers to sending data in packets through a network to some remote location. In a packet switched network, no circuit is left open on a dedicated basis. Packet switching is a data switching technique only.

PBX Phone System: Private Branch eXchange. Small version of the phone company's larger central switching office. An alternative to a PBX is to subscribe to a local telephone company's Centrex service.

PCMCIA (Personal Computer Memory Card International Association) PC Card: A credit card-size device used in laptop computers and available as removable network adapters.

PCS (Personal Communications Service): A new, lower powered, higher-frequency competitive technology to cellular. Whereas cellular typically operates in the 800-900 MHz range, PCS operates in the 1.5 to 1.8 GHz range. The idea with PCS is that the phone are cheaper, have less range, and are digital. The cells are smaller and closer together, and airtime is cheaper.

Peer-to-peer Network: A network design in which each computer shares and uses devices on an equal basis.

Ping: A troubleshooting TCP/IP application that sends out a test message to a network device to measure the response time.

PLD (Data Link Protocol): A raw packet protocol based on the Ethernet frame format. All frames are sent to the wireless network verbatim--should be used with care as improperly formatted data can go through with undesirable consequences.

Plug and Play: A feature that allows a computer to recognize the PCI adapter and configure the hardware interrupt, memory, and device recognition addresses; requires less user interaction and minimizes hardware conflicts.

Pocket PC: The term adopted by Microsoft and its supporters to describe handheld computers employing Microsoft's Pocket PC operating system.

Point-of-Sale Device: A special type of equipment that is used to collect and store retail sales data. This device may be connected to a bar code reader and it may query a central computer for the current price of that item.

POTS (Plain Old Telephone Service): The basic service supplying standard single line telephones, telephone lines, and access to the public switched telephone network.

Power Management: Algorithms that allow the adapter to sleep between checking for network activity, thus conserving power.

PSP (Power Save Polling): stations power off their radios for long periods. When a mobile unit in PSP mode associates with an access point, it notifies the AP of its activity status. The AP responds by buffering packets received for the MU.

PSTN (Public Switched Telephone Network): Refers to the worldwide voice telephone network accessible to all those with telephones and access privileges. In the U.S., the PSTN is provided by AT&T.


GlossaryQoS (Quality of Service): Measure of the telephone service quality provided to a subscriber. QoS refers to things like: Is the call easy to hear? Is it clear? Is it loud enough?

RBOC (Regional Bell Operating Company): One of the seven Bell operating companies set up after the divestiture of AT&T, each of which own two or more Bell Operating Companies (BOCs).

Roaming: Movement of a wireless node between two microcells. Roaming usually occurs in infrastructure networks built around multiple access points.

Repeater: A device used to extend cabling distances by regenerating signals.

Router: The main device in any modern network that routes data blocks from source to destination using routing tables and determining the best path dynamically. It functions as an addressable entity on the LAN and is the basic building block of the Internet.

SNMP (Simple Network Management Protocol): The network management protocol of choice for TCP/IP based intranets. Defines the method for obtaining information about network operating characteristics, change parameters for routers and gateways.

Scanning: A periodic process where the mobile unit sends out probe messages on all frequencies defined by the country code. The statistics enable a mobile unit to re-associate by synchronizing its frequency to the AP. The MU continues communicating with that access point until it needs to switch cells or roam.

Site Survey: Physical environment survey to determine the placement of access points and antennas, as well as the number of devices necessary to provide optimal coverage, in a new or expanding installation.

Spread Spectrum: A transmission technique developed by the U.S. military in World War II to provide secure voice communications, spread spectrum is the most commonly used WLAN technology today. It provides security by "spreading" the signal over a range of frequencies. The signal is manipulated in the transmitter so that the bandwidth becomes wider than the actual information bandwidth. De-spreading the signal is impossible for those not aware of the spreading parameters; to them, the signal sounds like background noise. Interference from narrowband signals is also minimized to background noise when it is de-spread by the receiver. Two types of spread spectrum exist: direct sequence and frequency hopping.

Stream Mode: A communications protocol supported only by the Telnet and TCP protocols. Stream mode transfers serial characters as they are received by encapsulating them in a packet and sending them to the host.


Glossary

T1: A type of dedicated digital leased-line available from a public telephone provider with a capacity of 1.544 Mbps. A T1 line can normally handle 24 voice conversations, each one digitized at 64 Kbps. With more advanced digital voice encoding techniques, it can handle more voice channels. T1 is the standard for digital transmission in the U.S. Canada, Hong Kong, and Japan.

TCP/IP: Networking protocol that provides communication across interconnected networks, between computers with diverse hardware architectures, and various operating systems. TCP/IP is used in the industry to refer to the family of common Internet protocols.

TCP (Transport Communication Protocol): Controls the transfer of data from one client to one host, providing the mechanism for connection maintenance, flow control, retries, and time-outs.

Telnet (Terminal Emulation Protocol): A protocol that uses the TCP/IP networking protocol as a reliable transport mechanism. Considered extremely stable.

Terminal: An endpoint, which provides for real-time, two-way communications with another terminal, gateway, or mobile unit.

Token Ring: A ring type of local area network (LAN) in which a supervisory frame, or token, must be received by an attached terminal or workstation before that terminal or workstation can start transmitting. Token ring is the technique used by IBM and others.

UDP (User Datagram Protocol): UDP/IP is a connection-less protocol that describes how messages reach application programs running in the destination machine; provides low overhead and fast response and is well suited for high-bandwidth applications.

Video Conferencing: Video and audio communication between two or more people via a video CODEC (coder/decoder) at either end and linked by digital circuits.

Voice Mail System: Device or system that records, stores, and retrieves voice messages. The two types of voice mail devices are those which are "stand alone" and those which offer some integration with the user's phone system.

Wi-Fi: A logo granted as the "seal of interoperability" by the Wireless Ethernet Compatibility Alliance (WECA). Only select wireless networking products possess this characteristic of IEEE802.11b.

Wireless AP Support: Access Point functions as a bridge to connect two Ethernet LANs.


Glossary

Wireless Local Area Network (WLAN): A wireless LAN is a data communications system providing wireless peer-to-peer (PC-to-PC, PC-to-hub, or printer-to-hub) and point-to-point (LAN-to-LAN) connectivity within a building or campus. In place of TP or coaxial wires or optical fiber as used in a conventional LAN, WLANs transmit and receive data over electromagnetic waves. WLANs perform traditional network communications functions such as file transfer, peripheral sharing, e-mail, and database access as well as augmenting wired LANs. WLANs must include NICs (adapters) and access points (in-building bridges), and for campus communications building-to-building (LAN-LAN) bridges.

Wireless Personal Area Network (WPAN): Personal area networks are based on a global specification called Bluetooth which uses radio frequency to transmit voice and data. Over a short range, this cable-replacement technology wirelessly and transparently synchronizes data across devices and creates access to networks and the Internet. Bluetooth is ideal for mobile professionals who need to link notebook computers, mobile phones, PDAs, PIMs, and other hand-held devices to do business at home, on the road, and in the office.

Wireless Wide Area Network (WWAN): Wide area networks utilize digital mobile phone systems to access data and information from any location in the range of a cell tower connected to a data-enabled network. Using the mobile phone as a modem, a mobile computing device such as a notebook computer, PDA, or a device with a stand-alone radio card, can receive and send information from a network, your corporate intranet, or the Internet.


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A Few References


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References (cont.)


Questions? Comments?

wireless sensor systems: security implications for the industrial environment

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