Global Positioning system (GPS) SPOOFING

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Global Positioning system (GPS) SPOOFING

• Yvon Feaster
• Cody Gentry
• Matt Rardon
• CPSC 420

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WHAT WE WILL COVER

• History of Global Positioning System (GPS)
• We will define spoofing and the different types.
• Why would someone want to spoof a GPS?
• Recent research on spoofing.
• Countermeasures.

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GPS What It Is And How It Works

• We all know what GPS is and have used it directly
  or indirectly
• How it works may be another story

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History of GPS

• GPS we use today is based off of earlier
  technologies
• Sputniks launch (1957)
• Scientists use the Doppler Effect to measure
  distance of its orbit
• Launch of Navys Transit System (1965)
• Used to guide Polaris missiles for submarines
• Launch of first NAVSTAR-GPS (1978)
• What we use today
• 24th satellite launched in 1993

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How It Works

• Each GPS receiver must know
• Where the satellites are
• How to accurately calculate time
• The speed of the radio signal from the satellite

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How It Works (contd)

• Triangulation is used
• Uses at least 4 satellites to ensure accuracy
• Measured by the intersection of each satellites
  signal-intercept radius
• A random signal is generated and repeated by both
  the satellite and receiver
• The lag time, or time it takes for the receiver
  to receive the signal travelling from the
  satellite, is used to calculate distance from the
  satellite

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Syncing Up
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Common Uses Today

• Police use it to find out the closest officer to
  an emergency
• Rescuers use it to find exact locations of
  stranded people
• For example miners were lost underground GPS
  used to find out where to excavate to find them.
• Used in navigation of airplanes, cars, etc.
• Scientist use it for its accurate and precise
  timing
• Timing to the billionth of a second
• Location up to 3 6 mm on the most accurate units

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WHAT IS SPOOFING

• Spoofing
• Def a generic term covering a range of computer
  network attacks whereby the attacker attempts to
  forge or intercede in a chain of
  communication.(http//www.standardchartered.com/o
  nline-banking/security-tips/glossary/en/q30)
• Def Spoofing refers to the process of
  replicating the GPS code so that the user
  computes incorrect position solutions. (http//ww
  w.modularmining.com/gps/glossary.htm)

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WHY SPOOF GPS?

• Monetary Gain
• Fishermen
• Waste Disposal
• Terrorism
• Power Generators
• Air Traffic Controllers
• Privacy Concerns
• Windows 7

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Types of Spoofing

• Software Code Spoofing
• Differential Corrections Spoofing
• GPS Signal Constellation Spoofing

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CURRENT RESEARCH

• Cornell / Virginia Tech

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CURRENT RESEARCH

• Argonne National Laboratories VAT
• 3 Steps
• Release receivers lock on GPS constellation
• Force receiver lock on spoofing satellite
• Continue broadcasting spoofing signal
• Can be achieved from 4586 ft away without direct
  LOS.

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COUNTERMEASURES

• Monitor the absolute GPS signal strength
• Monitor and record the average signal strength
• Compare the observed signal strength to the
  expected signal strength. If the absolute value
  of the observed signal exceed what is expected
  the receiver alerts the user
• This is an unambiguous indication of a spoofing
  attack
• This countermeasure takes minimal software changes

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COUNTERMEASURE 2

• Monitor the relative GPS signal strength
• Modify the receiver software to record and
  compare the average signal strength from one
  moment to the next.
• An extremely large change in the relative signal
  strength would indicate the beginning of a
  counterfeit GPS signal overriding the true
  satelite signal.
• If the signal increases beyond a preset point
  then the end user is notified.

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COUNTERMEASURE 3

• Monitor the strength of each received satellite
  signal
• This countermeasure is an extension of the first
  two countermeasures.
• The relative and absolute signals strengths are
  monitored for each incoming satellite.
• The signal coming from the artificial satellite
  tend to be of equal strength. Real satellite
  signal strengths vary and change over time.
  Therefore, if the signal strengths are too
  perfect this is an indication that the

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COUNTERMEASURE 4

• Monitor Satellite identification codes and the
  number of satellite signals received
• GPS satellite simulators transmit signals from
  multiple satellites (usually 10) which is more
  than the number of real signals detected by a GPS
  receiver in the field. Keeping track of both
  the number of satellite signals received and the
  satellite identification codes over time will
  help determine foul play.

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COUNTERMEASURE 5

• Check the time Intervals
• With most GPS satellite simulators, the time
  between the artificial signal from each satellite
  and the next is constant.
• Real satellite receivers will pick up a signal
  from one satellite and a few moments later pick
  up another.
• With satellite simulators the receiver picks up
  signals from all of the satellites
  simultaneously.
• This will alert the user that there is a problem.

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COUNTERMEASURES 6

• Do a time comparison
• Many current GPS receivers do not have an
  accurate clock.
• By using timing data from an accurate,
  continuously running clock to compare with the
  time derived from the GPS signal, we can check
  the validity of the received GPS signal.

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COUNTERMEASURES 7

• Perform a sanity check
• A small, solid-state accelerometer and compass
  can be used to independently monitor the physical
  trajectory of the receiver.
• The information provided by this approach can be
  used to check the current position reported by
  the GPS based on the previously reported
  position.

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RECAP

• We covered the history of GPS
• We defined spoofing and talked about different
  types of spoofing
• We gave you examples of why a GPS might be
  spoofed
• We talked about current research on spoofing GPS
• Lastly, we talked about ways to combat spoofing.

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REFERENCES

• Bland, Eric. "GPS 'spoofing' could threaten
  national security." 02 Oct. 2008.MSNBC.28 Nov.
  2008 ltgps 'spoofing' could threaten national
  securitygt.
• Cornell Chronicle Online - http//www.news.cornell
  .edu/stories/Sept08/GPSSpoofing.aj.html
• Diaz, Jesus. "Windows 7's New Geolocation Service
  Introduces Privacy Problems." Gizmodo. 10 Nov.
  2008. 28 Nov. 2008 lthttp//gizmodo.com/5082276/win
  dows-7s-new-geolocation-service-introduces-privacy
  -problemsgt.
• Discovery.com GPS Spoofing Could Threaten
  National Security http//dsc.discovery.com/news/20
  08/10/02/gps-spoofing.html
• History of GPS (http//usinfo.state.gov/xarchives/
  display.html?pwashfileenglish
• y2006mFebruaryx20060203125928lcnirellep0.5061
  609) ", usinfo.state.gov(http//usinfo.state.gov/)
  (February 3, 2006).
• Humphreys, T.E., B.M. Ledvina, M.L. Psiaki, and
  P.M. Kitner, Jr. "Assessing the Spoofing Threat
  Development of a Portable GPS Civilian Spoofer."
  Sept. 2008. Institution of Navigation. 28 Nov.
  2008 lthttp//www.ion.org/meetings/gnss2008/abstrac
  ts.cfm?trackcsession5gt.

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REFERENCES CONTINUED

• Ju, Anne. "Spoofing GPS Receivers." Cornell
  Chronicle. 19 Sept. 2008.Cornell University.28
  Nov. 2008 lthttp//www.news.cornell.edu/stories/sep
  t08/gpsspoofing.aj.htmlgt.
• National Academy of Science, 2003 GPS_ The Role
  of Atomic Clocks Text View.pdf
  http//www.beyonddiscovery.org/content/view.txt.as
  p?a458 
• RMBL How GPS Actually Works.pdf
  http//thermbl.googlepages.com/howgpsactuallyworks
  
• Scott, Logan. "Expert Advice -- Location
  Assurance." GPS World. 01 July 2007. 28 Nov. 2008
  lthttp//sidt.gpsworld.com/gpssidt/content/printcon
  tentpopup.jsp?id436920gt.
• Sherri. "GPS Spoofing." Philosecurity. 7 Sept.
  2008. 28 Nov. 2008 lthttp//philosecurity.org/2008/
  09/07/gps-spoofinggt.
• Uses for GPS.pdf 
• Warner, Jon S., Ph.D. and Johnston, Roger G.,
  Ph.D., CPP, GPS Spoofing Countermeasures 2003
  http//www.homelandsecurity.org/bulletin/Dual20Be
  nefit/warner_gps_spoofing.html

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QUESTIONS