www.Mohammad.Ehdaie.com Introduction to Ad-hoc & Sensor
Networks Security In The Name of God ISC Student Branch in KNTU 4
th Workshop Ad-hoc & Sensor Networks Security Slide 2 Outline
Ad-hoc Networks Sensor Networks Motivation for Security Issues Key
Distribution Schemes Some Basic Schemes Calculation of Their
Parameters An Improvement April 14-15, 2011 Intro. to Ad-hoc &
Sensor Networks Security 2 Slide 3 Outline Ad-hoc Networks Sensor
Networks Motivation for Security Issues Key Distribution Schemes
Some Basic Schemes Calculation of Their Parameters An Improvement
April 14-15, 2011 Intro. to Ad-hoc & Sensor Networks Security 3
Slide 4 Ad-hoc Network: Motivation April 14-15, 2011 Intro. to
Ad-hoc & Sensor Networks Security 4 Slide 5 Ad-hoc Network:
Properties Without any Infrastructure (Self-Organized) Minimal
Configuration & Quick Deployment Dynamic Topology Each Node
Participates in Routing Constrained Resources Battery Power
Wireless Transmitter Range Computational Power April 14-15, 2011
Intro. to Ad-hoc & Sensor Networks Security 5 Slide 6 Ad-hoc
Network: Applications Started by DARPA (1970s) Military Conflicts
Emergency Services or Natural Disasters Commercial Environments
Location-Aware Services Entertainment April 14-15, 2011 Intro. to
Ad-hoc & Sensor Networks Security 6 Slide 7 Outline Ad-hoc
Networks Sensor Networks Motivation for Security Issues Key
Distribution Schemes Some Basic Schemes Calculation of Their
Parameters An Improvement April 14-15, 2011 Intro. to Ad-hoc &
Sensor Networks Security 7 Slide 8 Sensor Network: Definition A
Collection of Sensors Gathering and Sending Information
Self-Organized Similar to Ad-hoc Network Monitoring Sending Alarms
On-Demand Querying Information April 14-15, 2011 Intro. to Ad-hoc
& Sensor Networks Security 8 Slide 9 Sensor Node Micro
Controller Radio Transceiver Battery Sensor Temperature Motion
Pollution April 14-15, 2011 Intro. to Ad-hoc & Sensor Networks
Security 9 Slide 10 Sensor Network: Applications Battlefield
Surveillance Industrial Process Monitoring Environment Monitoring
Forest Fire Detection Air Pollution Monitoring Greenhouse (Humidity
& Temperature) Health Care (Tracking Patients, ) Traffic
Control Home Automation April 14-15, 2011 Intro. to Ad-hoc &
Sensor Networks Security 10 Slide 11 Sensor Network: Properties
Lots of Sensors Spread Randomly over Target Area Not Controlled by
Human No Movement (often) Size & Cost Constraints More Tight
Constraints on: Power Consumption Memory Size Computational Power
Communicational Power April 14-15, 2011 Intro. to Ad-hoc &
Sensor Networks Security 11 Slide 12 Outline Ad-hoc Networks Sensor
Networks Motivation for Security Issues Key Distribution Schemes
Some Basic Schemes Calculation of Their Parameters An Improvement
April 14-15, 2011 Intro. to Ad-hoc & Sensor Networks Security
12 Slide 13 Security Issues Vulnerabilities: Broadcast Channel
Physical Access to Nodes Cannot be made Tamper Proof Why Standard
Models Are not Applicable? Computational Constraints Memory
Constraints Infeasibility of Public-Key Cryptosystem Some More
Considerations on Private -Key Cryptosystem April 14-15, 2011
Intro. to Ad-hoc & Sensor Networks Security 13 Slide 14 Key
Management Key Distribution (or Pre-Distribution) Key Discovery Key
Establishment Key Update April 14-15, 2011 Intro. to Ad-hoc &
Sensor Networks Security 14 Slide 15 Key Distribution Which node
should store which keys? April 14-15, 2011 Intro. to Ad-hoc &
Sensor Networks Security 15 Slide 16 Outline Ad-hoc Networks Sensor
Networks Motivation for Security Issues Key Distribution Schemes
Some Basic Schemes Calculation of Their Parameters An Improvement
April 14-15, 2011 Intro. to Ad-hoc & Sensor Networks Security
16 Slide 17 Trivial Schemes April 14-15, 2011 Intro. to Ad-hoc
& Sensor Networks Security 17 Single Master Key Distinct
Pair-wise Keys Large Memory Low Security Infeasible Slide 18
Evaluation Metrics Memory Usage Connectivity Processing Overhead
Communication Overhead Resiliency Against Node Capture April 14-15,
2011 Intro. to Ad-hoc & Sensor Networks Security 18 Slide 19
Evaluation Metrics (contd) April 14-15, 2011 Intro. to Ad-hoc &
Sensor Networks Security 19 Fail (s) = % Compromised Links When s
Nodes Are Compromised Fail(s) s 1 1 Single Master Key Fail(s) s 1 1
2/N N-1 Distinct Pair-wise Keys Slide 20 Classification- I April
14-15, 2011 Intro. to Ad-hoc & Sensor Networks Security 20
DeterministicProbabilistic Large Number of Keys 2 Keys in each node
Connected Communicational & Computational Overhead Arbitrary
Features Slide 21 Classification- II April 14-15, 2011 Intro. to
Ad-hoc & Sensor Networks Security 21 Location Independent
Location aware Better PerformanceMore Realistic Slide 22
Classification- III April 14-15, 2011 Intro. to Ad-hoc & Sensor
Networks Security 22 Homogenous Hierarchical Resilient against more
overhead Easier to Establish- More Realistic Slide 23 Outline
Ad-hoc Networks Sensor Networks Motivation for Security Issues Key
Distribution Schemes Some Basic Schemes Calculation of Their
Parameters An Improvement April 14-15, 2011 Intro. to Ad-hoc &
Sensor Networks Security 23 Slide 24 Blom Polynomial Scheme April
14-15, 2011 Intro. to Ad-hoc & Sensor Networks Security 24 m m
n n Slide 25 EG Probabilistic Scheme April 14-15, 2011 Intro. to
Ad-hoc & Sensor Networks Security 25 Connected with arbitrary
probability near 1 Slide 26 Liu Scheme April 14-15, 2011 Intro. to
Ad-hoc & Sensor Networks Security 26 Slide 27 Transversal
Design Scheme April 14-15, 2011 Intro. to Ad-hoc & Sensor
Networks Security 27 Slide 28 Outline Ad-hoc Networks Sensor
Networks Motivation for Security Issues Key Distribution Schemes
Some Basic Schemes Calculation of Their Parameters An Improvement
April 14-15, 2011 Intro. to Ad-hoc & Sensor Networks Security
28 Slide 29 Fail(s) for EG Scheme It is claimed that Fail(1) = k/P
sometimes < 2/n Assumption: 1 node is captured Event A = An
arbitrary link is compromised Event B = The captured node is one
end of the considered link Fail(1) = Pr{A} = Pr{A|B}Pr{B} +
Pr{A|B}Pr{B} Pr{B} = 2/n Pr{B} = 1 2/n Pr{A|B} = 1 Pr{A|B} = k/P
fail(1) = 1 * 2/n + k/P * (1-2/n) 2/n + k/P April 14-15, 2011
Intro. to Ad-hoc & Sensor Networks Security 29 Slide 30
Comparison April 14-15, 2011 Intro. to Ad-hoc & Sensor Networks
Security 30 SchemeAvg hopsMemoryFail(1) Pair-wise1n-12/n Blom1k2/n.
EG2-qk2/n + k/P Liu 2-k/(n-1) 2 k=n/m+m-2 2n < k < n-1 2/n
TD(k,n)1 Slide 31 Outline Ad-hoc Networks Sensor Networks
Motivation for Security Issues Key Distribution Schemes Some Basic
Schemes Calculation of Their Parameters An Improvement April 14-15,
2011 Intro. to Ad-hoc & Sensor Networks Security 31 Slide 32 An
improvement to EG April 14-15, 2011 Intro. to Ad-hoc & Sensor
Networks Security 32 Slide 33 An improvement to EG April 14-15,
2011 Intro. to Ad-hoc & Sensor Networks Security 33 Slide 34
Result April 14-15, 2011 Intro. to Ad-hoc & Sensor Networks
Security 34 Pr{Share a common Key} Memory Size Slide 35 Resiliency
against node capture Broken Completely: 2 / n + k 2 / P 2 2k / P of
links (Half Security) April 14-15, 2011 Intro. to Ad-hoc &
Sensor Networks Security 35 Slide 36 References April 14-15, 2011
Intro. to Ad-hoc & Sensor Networks Security 36 [1] R. Blom, "An
optimal class of symmetric key generation systems", in: T. Beth, N.
Cot, I. Ingemarsson (eds.), Advances in Cryptology -EUROCRYPT 84,
vol. 209 of LNCS, Springer-Verlag, pp. 335338, 1985. [2] C. Blundo,
A. D. Santis, A. Herzberg, S. Kutten, U. Vaccaro, M. Yung,
"Perfectly-secure key distribution for dynamic conferences", in: E.
F. Brickell (ed.), Advances in Cryptology -CRYPTO 92, vol. 740 of
LNCS, Springer-Verlag, pp. 471486, 1992. [3] Y. Cheng, D. P.
Agrawal, An improved key distribution mechanism for large-scale
hierarchical wireless sensor networks, ELSEVIER Ad Hoc Networks 5,
pp. 3548, 2007. [4] J. Lee, D. R. Stinson, "On the construction of
practical key predistribution schemes for distributed sensor
networks using combinatorial designs", ACM Trans. Inf. Syst. Secur.
11 (2), pp. 135, 2008. [5] S. A. Camtepe, B. Yener, "Key
distribution mechanisms for wireless sensor networks: a survey",
Tech. Rep. TR-05- 07, Rensselaer Polytechnic Institute, 2005. [6]
K.M. Martin, M.B. Paterson, D.R. Stinson."Key Predistribution for
Homogeneous Wireless Sensor Networks with Group Deployment of
Nodes". Cryptology ePrint Archive, 2008. [7]A. Parakh, S. Kah, "A
Key Distribution Scheme for Sensor Networks Using Structured
Graphs", arxiv e-Print archive, 2010. Slide 37 References April
14-15, 2011 Intro. to Ad-hoc & Sensor Networks Security 37
[8]J. Lopez, J. Zhou. "Wireless Sensor Network Security". IOS
Press, 2008. [9] M. Ren, J. Jaworski, K. Rybarczyk, "Random key
predistribution for wireless sensor networks using deployment
knowledge", 8th Central European Conference on Cryptography, 2008.
[10] H. Chan, A. Perrig, D. Song, "Random Key Predistribution
Schemes for Sensor Networks", Proceedings of the 2003 IEEE
Symposium on Security and Privacy, p.197, 2003. [11]L. Eschenauer,
V.D. Gligor. "A Key-Management Scheme for Distributed Sensor
Networks". Proceedings of the 9th ACM conference on Computer and
communications security, pp 41-47, 2002 Slide 38 April 14-15, 2011
Intro. to Ad-hoc & Sensor Networks Security 38 Thank you!
