Security in Wearble Sensor Platforms Present and Future

1
Security in Wearble Sensor Platforms Present
and Future

• Ayan Banerjee Karthik Thangavel

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Project Goals

• Study of present state of security in Body Area
  Networks(BAN)
• Cyber-Physical security
• Resource Footprint
• Energy efficiency
• Sustainability
• Effect of security on present day BANs
• Vision of security in future wearable sensor
  platforms
• Intel Atom based wearable platforms

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Body Area Networks (BAN)
EEG
Sensors
EKG
BP
SpO2
Base Station
Base Station
Environmental sensors
Physiological sensors
Activity sensors
Motion Sensor

• A network of low capability sensors
  (physiological, environmental and activity
  monitoring)
• Sensors communicate with each other through
  wireless media
• Base Station is a gateway for the sensors to the
  internet

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Security in BAN

• Why ?
• BANs deal with sensitive information
• Wireless media open to security breaches
• Requirements
• Integrity
• Confidentiality
• Authentication
• Plug-n-Play

• Non intrusive and low deployment overhead
• Traditional Schemes not applicable
• Can a cyberphysical approach provide the
  solution?

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Cyber-Physical Security
Use this to provide security
Interaction through sensing
The term Cyber-physical implies interaction of
computing world with the physical environment
Feedback
Cryptographic primitives
Cyber-Physical Security
Signal Processing
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PKA
PV
PV
SENSOR 2
SENSOR 1
Sensing
Sensing
Time
Time
FFT Values
FFT Values
FFT
FFT
Index
Index
Peak Values
Peak Values
Peak Detection
Peak Detection
Index
Index
Quantize
Quantize
Fs fs1 fs2 .. fsn
Fr fr1 fr2 .. frn
p(fs1)
Polynomial Generation and evaluation
p(fs2)
p(fsn)
fs1
fsn
fs2
Adding Chaff

• Extensive experiments with Plethysmogram data
• Data obtained from 10 volunteers
• Data collected using Smith Medical pulse oximeter
  boards
• Processing done in MATLAB environment

Receive Vault
R
Transmit Vault
Lagrangian Interpolation
p(x)
Receive Acknowledgement
Transmit Acknowledgement
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Related Work

• PKI based security 1
• The idea of using signals from environment to
  provide security was first proposed in 2 and
  3
• 3 proposed an algorithm to generate security
  keys from localized measurements of Inter Pulse
  Interval signals.
• 4 proposes a secure key agreement protocol PKA
  (Physiological value based Key Agreement)

• D. J. Malan, M. Welsh, and M. D. Smith. A
  Public-Key Infrastructure for Key Distribution in
  TinyOS Based on Elliptic Curve Cryptography.
  pages 7180, Oct 2004. In Proc. of IEEE 2nd Intl.
  Conf. on Sensor Ad Hoc Comm. Networks.
• S. Cherukuri, K. Venkatasubramanian, and S. K. S.
  Gupta. BioSec A Biometric Based Approach for
  Securing Communication in Wireless Networks of
  Biosensors Implanted in the Human Body. pages
  432439, Oct 2003. In Proc. of Wireless Security
  Privacy Workshop 2003.
• K. Venkatasubramanian and S. K. S. Gupta.
  Security for Pervasive Health Monitoring Sensor
  Applications. pages 197202, Dec 2006. In Proc.
  of the 4th Intl. Conf. on Intelligent Sensing
  Information Processing.
• C. C. Y. Poon, Y.-T. Zhang, and S.-D. Bao. A
  Novel Biometrics Method To Secure Wireless Body
  Area Sensor Networks for Telemedicine And
  M-Health. IEEE Communications Magazine,
  44(4)7381, 2006.
• K. K. Venkatasubramanian, A. Banerjee, and S. K.
  S. Gupta. Plethysmogram-based secure inter-sensor
  communication in body area networks. Military
  Communications Conference, 2008. MILCOM 2008.
  IEEE, pages 1-7, Nov. 2008.

Resource Usage ?
Energy Efficiency ?
Sustainability ?
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Resource Footprint

• TelosB sensors
• 8 MHz clock
• 10 KB RAM
• TinyOS operating system that supports NesC

• 70 of RAM utilization
• Near 100 ROM usage
• 20 seconds to perform a single iteration

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Experimental Setup for power measurement

• Bread board circuit for power measurement

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Energy Efficiency sustainability

• 59 mW of power required for 20 seconds to perform
  one iteration
• Offhand analysis of scavenging techniques
• Body Heat 200 mW
• Respiration 420 mW
• Ambulation 1500 mW
• Solar Power 100 mW/cm2
• PKA can be sustained using scavenged energy

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Effect of security in present day BAN

• Pros
• Secure
• Energy efficient
• Sustainable
• Cons
• High memory usage
• Applications getting complex
• Security will be obtrusive
• Require more and more computing in sensor nodes

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Vision of a future BAN
Present
Future

• Intel Atom based sensors as nodes ?
• High computing capability
• 1.6 GHz processor
• 512 KB L1 cache

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Open research questions

• Can we guarantee energy efficient operation of
  Atom based platforms?
• Can we sustain Atom operation through scavenging
  of energy?
• What effect does the power dissipation in Atom
  has on human body?
• Do we need changes in the security protocols in
  order to sustain operation of Atom based
  platforms?

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Off hand analysis

• Atom requires 2W of power at normal operation and
  0.5 W in deep sleep states.

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Conclusions

• Security has huge resource overhead on present
  day wireless sensor platforms
• Sensor node capability have to be increased in
  order to provide security along with complex
  applications
• Atom based platforms are promising

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Thank You