This document outlines key aspects of pervasive computing including: 1. It discusses the evolution of computing from mainframes to personal computers to the emerging era of pervasive computing. 2. It describes the architecture of pervasive computing including applications, middleware, intelligent computing, mobile computing, context-awareness and affective computing components. 3. It examines wireless communication technologies used in pervasive computing like Zigbee, Bluetooth, WiFi and discusses security issues with vulnerabilities in these wireless systems including denial of service attacks, eavesdropping and message injection.

1. SOK Phearin
Department of Computer Science
MBC Lab., Konkuk University
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2. Outline
I. Overview of Pervasive Computing
II. Architecture
III. Wireless Communication Technologies in Pervasive
Computing and Security Issues
IV. Wireless Vulnerabilities
V. Conclusion
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3. Pervasive Computing Overview
“Ubiquitous computing names the third wave in computing, just
now beginning. First were mainframes, each shared by lots of
people. Now we are in the personal computing era, person and
machine staring uneasily at each other across the desktop. Next
comes ubiquitous computing, or the age of calm
technology, when technology recedes into the background of our
lives.”
“The Computer for the 21st Century”
- September, 1991
Mark D. Weiser (July 23, 1952 – April 27, 1999)3

4. Pervasive Computing Overview
Development of computing technologies:
 1st wave : Mainframe computing era
 2nd wave : Personal computing era
 3rd wave : Pervasive computing era
(initially called ubiquitous computing)
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5. What is Pervasive Computing
 Integration of Information and Communications
Technology (ICT) into people’s lives and
environments, made possible by the growing availability
of microprocessors with inbuilt communication
facilities.
 Goals:
 People Oriented
 Implicitly use of computers
 People will focus on task, not tool
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6. Pervasive Computing Components
Three converging areas of ICT components:
 Computing devices: communicate with each other and
act intelligently
 Sensors: input devices
 Processors: interpret and analyze data
 Actuators: output devices
 Communications: serve pervasive computing applications
Ex. Zigbee, Bluetooth, WiFi, Wimax /LTE /3G /4G …
 User Interfaces: point of contact between ICT and human
 Active: Users overtly control PC technologies and devices
 Passive: PC covertly control in the background
 Coercive: both Active and Passive
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7. Architecture
Application
Middleware and Security Interface
Various applications such as
Smart Room, Intelligent
Intelligent Computing
Mobile Computing
Navigation… can be built and
Context-Aware used
Affective Computing
Embedded Operating System
Hardware
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8. Architecture
Application Not only:
Middleware and Security Interface  Heterogeneity
 Scalability
Intelligent Computing
Mobile Computing  Programming interface
Context-Aware
But also:
Affective Computing  Service Discovery
 Context-aware
Embedded Operating System
Hardware
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9. Architecture
Structure of Middleware and Security Interface
API
Context-aware
service
Service Description
Extend Module
……
Security Mechanism
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10. Architecture
Application
Middleware and Security Interface
An important aspect of the
Intelligent Computing
Mobile Computing difference between pervasive
computing and desktop
Context-Aware computing
Affective Computing
Embedded Operating System
Hardware
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11. Architecture
Mobile Computing:
•Automatic configuration, dynamic addressing and tracking system
•Free switch between heterogeneous networks
Affective Computing is the computing that relates to, arises
from, or deliberately influences emotions.
– Rosalind W. Picard
•computer science, sensor technology, psychology, physiology
•Key technologies: face recognitions, emotional signal
measurements and analysis
Context-aware Computing: senses environment context and
human context changes.
Key technologies: Location awareness, activities recognition
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12. Architecture
Application Hardware:
Middleware and Security Interface  Fast processing speed
 Small size
Intelligent Computing
Mobile Computing
Context-Aware Embedded Operating
System:
Affective Computing
 Real-time services
 Rational allocation
Embedded Operating System memories
Hardware
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13. Architecture
Structure of Embedded Operating System and Hardware
Network
Sensors I/O Device
Interface
Real-time Embedded Operating System
Pervasive Computing Hardware
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14. Wireless Communication
Many existing and emerging wireless technologies
serve in Pervasive Computing:
•Zigbee and Bluetooth - sensors and actuators - low
energy consumption, short distances (up to 10 meters)
•Wi-Fi - devices - middle ranges (several hundreds of meters)
•Wimax /LTE /3G /4G - a home gateway to Internet - long
ranges (several to tens of kilometres)
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15. Security Issues
Common vulnerabilities existing in wireless technologies:
 Physical jamming
 Passive eavesdropping and traffic analysis
 Message injection and active eavesdropping
 Message deletion and interception
 Insider attacks to breach data confidentiality
 Denial of service (DoS) attacks
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16. Security Issues
Various types of Attack to a Pervasive Computing can:
 Compromise users’ data,
 Crash an entire system
 Render services unavailable
 Potentially lead to the loss of property
 Harm users and even lives
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17. Wireless Vulnerabilities
Wi-Fi MAC Protocol Attacks
 Carrier Sense Multiple Access with Collision Avoidance
(CSMA/CA)
 DoS attack: Clear Channel Assessment-Jamming
 Virtual carrier sense
 DoS attack: Repeat forged RTS/CTS messages with large
NAV leading network slowdown
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18. Wireless Vulnerabilities
 802.11 state machine
 DoS attack: forge deauthentication or disassociation frames
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19. Wireless Vulnerabilities
Wi-Fi Security Protocol Attacks
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20. Wireless Vulnerabilities
Wi-Fi Security Protocol Attacks
Pre-Robust Security Network Association (Pre-RSNA):
security mechanisms in the IEEE 802.11-1997
 Attacks on Wired Equivalent Privacy(WEP):
 Shared Key management – key can be easily obtained from the
attackers
 Weak RC4 encryption implementation – key can be easily broken
by the brute force attack
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21. Wireless Vulnerabilities
Robust Security Network Association (RSNA): security
mechanisms in the IEEE 802.11-2007,
consisting of 3 security algorithms:
Data confidentiality and integrity protocols
RSNA security association management
key management procedures
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22. Wireless Vulnerabilities
Attacks on RSNA
•Security level rollback attack: “Pre-RSNA only” beacons to force
the network to use WEP
•EAP attack: forged association requests - disconnect legitimate
users.
•Four-way handshake DoS attack: forged first unauthenticated
message - parallel incomplete Handshakes - exhaust queue
space
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23. Wireless Vulnerabilities
Attacks on RSNA (Cont.)
•RSN IE poisoning: fake beacons - fail at stage 3
•Reflection attack against four-way handshake: transmitted
data sent back to originator .
•Dos attack against TKIP: intercepted and modified packet - AP
and the client suspend their communication
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24. Conclusion
 Confidentiality, Integrity, and Availability (CIA) are
essential to pervasive computing applications since
sensitive and real-time information may flow over any type
of wireless links
 Many challenges and attacks have been proved. Each
operation and policy should be carefully examined against
any possible attacks.
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25. Reference
 Liu, Y. & Li, F., PCA: A Reference Architecture for Pervasive Computing, 2006 1 st
International Symposium on Pervasive Computing and Applications, IEEE
04079121
 Zhou, B, Marshall, A. & Lee, T. H., Wireless Security Issues in pervasive
computing, 2010 Fourth International Conference on Genetic and Evolutionary
Computing, IEEE 05715481
 2006, Pervasive Computing, Parliamentary Office of Science and Technology
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