This document presents a major work on the necessity and implementations of public key cryptography (PKC) in wireless sensor networks (WSNs). It discusses how PKC can provide benefits over symmetric key cryptography for WSNs, including increased security and flexibility. It also addresses the challenges of implementing PKC in resource-constrained WSNs and compares different approaches like software, hardware, and blended implementations. The document concludes by recommending the selection of suitable PKC schemes based on network topology and optimizing PKC protocols for sensor networks.

1. Major Works on the Necessity and
Implementations of PKC in WSNs
Presented By: Vijay Soppadandi
Pursuing M.Sc in Applied CS
Semester: Third
ID number: 21363273
1
Institute of Informatics Georg-August-Universitaet Goettingen, Germany
Department of Telematics
Proffesor : Dr. Dieter Hogrefe
Supervisor: Dr. Parisa Memarmoshref
Advisor : Hang Zhang
Course: Security of Self-organizing Networks

2. Wireless Sensors
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Institute of Informatics Georg-August-Universitaet Goettingen, Germany
Department of Telematics Course: Security of Self-organizing Networks
o Low power electronic devices
o Integrated wireless communication
capabilities
Eg., Mica Mote:
Processor: 4Mhz
Memory: 128KB Flash and 4KB RAM
Radio: 916Mhz and 40Kbits/second.
Transmission range: 100 feet

3. Overview
Wireless sensor networks
WSNs security issues
Security threats and issues in WSNs
Goals of WSNs
PKC vs SKC
Advantages of PKC
How PKC works in WSNs
Cases for WSNs
Challenges
Types of implementations
Comparing different types of implementations
Recommendations
References
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Institute of Informatics Georg-August-Universitaet Goettingen, Germany
Department of Telematics Course: Security of Self-organizing Networks

4. Wireless Sensor Netwotks (WSNs)
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Institute of Informatics Georg-August-Universitaet Goettingen, Germany
Department of Telematics Course: Security of Self-organizing Networks
Gateway
network
Server: N/w &
Security manager
nodes

5. WSN Applications
• Environmental monitoring
War-fare, child education, surveillance, microsurgery and agriculture
• Smart buildings
Reduces the energy consumptions by controlling room temperature
• Hospital tracking systems
Tracking patients, doctors, drug administrators
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Institute of Informatics Georg-August-Universitaet Goettingen, Germany
Department of Telematics Course: Security of Self-organizing Networks

6. WSN security
• Why do we care about security in WSN?
• Why previous security techniques are not
enough?
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Institute of Informatics Georg-August-Universitaet Goettingen, Germany
Department of Telematics Course: Security of Self-organizing Networks

7. Security threats and issues in WSN
• Security attacks are broadly classified into two categories
1) Passive Attacks
- Monitoring and Eavesdroping
- Comouflage Adversaries
2) Active Attacks
- Routing Attacks in Sensor Networks:
* Attacks on Information in transit
* Black hole / sink hole Attack
nodes
Base station
Attacker 7
Institute of Informatics Georg-August-Universitaet Goettingen, Germany
Department of Telematics Course: Security of Self-organizing Networks
B

8. Security threats and issues in WSN
• Wormholes Attacks
- Attacker records the packets at one location in N/W and tunnels those
to another location.
Attacker
Worm hole
Link
• Many others logical and physical attacks in WSNs
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Institute of Informatics Georg-August-Universitaet Goettingen, Germany
Department of Telematics Course: Security of Self-organizing Networks
B Z
Y

9. Goals of WSNs
• Basic primary goals are:
- Data Confidentiality, Integrity, Authenticity and Availability (CIAA)
• Secounday goals are:
- Data freshnes: Needs to ensure the freshness of each message
- Self Organization: Sensor node be independent and flexible enough to be self-healing
- Secure Localization: Each and individual sensor must accurately automatically locate each
sensor in the network
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Institute of Informatics Georg-August-Universitaet Goettingen, Germany
Department of Telematics Course: Security of Self-organizing Networks

10. Basic comparission of PKC and SKC
 PKC (Public Key Cryptography)
• Two different keys
• PKC was not preffered for low-resource contrained devices
• Energy inefficient, slow and computational complex
 SKC ( Symmetric Key Cryptography)
• Similar keys
• It prefered for for low-resourse constrained devices
• Its not energy inefficient, slow and computational complex
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Institute of Informatics Georg-August-Universitaet Goettingen, Germany
Department of Telematics Course: Security of Self-organizing Networks

11. Advantages of PKC
• The primary advantage of PKC is increased security and
convenience
• It can provide digital signatures that cannot be repudiated
• PKC-based Key Distribution
-100% resilience
-100% connectivity
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Institute of Informatics Georg-August-Universitaet Goettingen, Germany
Department of Telematics Course: Security of Self-organizing Networks

12. PKC in WSNs
• Two keys are generated
• Public key is open to all and private is belongs to owner
Ciphertext (C)
Base station (BS)
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Institute of Informatics Georg-August-Universitaet Goettingen, Germany
Department of Telematics Course: Security of Self-organizing Networks
EPUB(M)->C
M
Key generator
DPRI(C)->M
Memorysensor
Public key
(PUB)

13. Cases for WSNs
 Complexity of key management and storage requirements in some
network settings:
- PKC allows flexiable key mangment
- Why not SKC? : Because of its complex broadcasting authentication
and delayed key disclosure
- A proper time synchronization
 Absence of pairwise key
- nodes in N/W need to send their reading to Base station, If pair
wise keys are not exist.
- PKC is useful in this case
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Institute of Informatics Georg-August-Universitaet Goettingen, Germany
Department of Telematics Course: Security of Self-organizing Networks

14. Cases for WSNs
 Offline processing and number of keys in some networks settings
- SKC needs to store a large amount keys in storage in sensor
memories before their deployment
- It increases burden and often demands more storage
- Where as in PKC, public key of the BS is embedded into sensors
 Scalability of a network
- PKC doesnt have scaliabilty problem
 Better protection under physical capture scenario
- SKC has high probability of damage if the nodes use same secreat key
- PKC can be used to establish the symmetric session keys
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Institute of Informatics Georg-August-Universitaet Goettingen, Germany
Department of Telematics Course: Security of Self-organizing Networks

15. Challenges to implement PKC in WSNs
• Enegry consumption, communication costs, computational
complexity, time complexity, security
Major barriers to implement are:
 Constrained resourse of the sensors:
Inadequate memory, processing and communication capabilities
not support excecute large amount of code
• Wireless medium:
Allows an attacker to easily intercept valid packets and inject
malicious ones
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Institute of Informatics Georg-August-Universitaet Goettingen, Germany
Department of Telematics Course: Security of Self-organizing Networks

16. Challenges to implement PKC in WSNs
• Hostile Environment:
This high hostile environment represents a serious
challange forsecurity researchers
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Institute of Informatics Georg-August-Universitaet Goettingen, Germany
Department of Telematics Course: Security of Self-organizing Networks

17. Types of Implementations
PKC-based mechanisms can be categorized mainly into
three approaches
a) Software implementations
b) Hardware implementations
c) Hardware/software blended implementations
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Institute of Informatics Georg-August-Universitaet Goettingen, Germany
Department of Telematics Course: Security of Self-organizing Networks

18. Comparing different types of implementations
18
Institute of Informatics Georg-August-Universitaet Goettingen, Germany
Department of Telematics Course: Security of Self-organizing Networks

19. Recommendations and future expectations
• Select the most suitable PK schemes based on the
topologies and the scenarios of WSN
• Next generation sensor nodes are expected to have more
energies
• Optimizing public-key protocols for sensor networks
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Institute of Informatics Georg-August-Universitaet Goettingen, Germany
Department of Telematics Course: Security of Self-organizing Networks

20. References
Major Works on the Necessity and Implementations of PKC in
WSNs, author: AL-sakib Khan Pathan ,pp.525-545
Puccinelli, D., & Haenggi, M. (2005). Wireless sensor
networks: applications and challenges of ubiquitous sensing.
Circuits and Systems Magazine, IEEE, 5(3), 19-31.
Kumar, Vikash, Anshu Jain, and P. N. Barwal. "Wireless Sensor
Networks: Security Issues, Challenges and Solutions."
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Institute of Informatics Georg-August-Universitaet Goettingen, Germany
Department of Telematics Course: Security of Self-organizing Networks

21. END
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Institute of Informatics Georg-August-Universitaet Goettingen, Germany
Department of Telematics Course: Security of Self-organizing Networks