A Pairwise Key Security Scheme Suits Topology Control Protocols, 2nd afro european workshop 9 feb 2015

This project is funded by Structural Funds of the European Union and state budget of the Czech Republic

A Pairwise Key Security Scheme

Suits

Topology Control Protocols

Mohamed Mostafa Fouad, PhD.

Arab Academy for Science, Technology, and Maritime Transport.

Postdoc Fellow at VSB-Technical University of Ostrava, Czech Republic.

Member at SRGE Research Group (www.egyptscience.net).

http://www.egyptscience.net/


Agenda • WSN: An Overview– WSN Design challenges

• Security Challenges

– Security Solutions

– Pairwise Key Schemes

• Topology Control (TC) Basic Idea

– The A3 Topology Control Protocol

• Proposed Schemes

• Conclusions


• WSN: An Overview– WSN Design challenges







• Conclusions

1

WSN: An Overview

Agenda


WSN: An Overview


WSN Design challenges

Resource Constraints

DepletableEnergy Source

Security & Privacy

Distribution Strategy

Fault Tolerance

Heterogeneity









• Conclusions

2

Security Challenges &

Solutions

Agenda


Challenges

• Security


Security Solutions

Any Security Solution Should:

Providing the capability of node-

to-node secure communication

without any control from the base

station.

The future added nodes can easily perform a secure communication

channel with the previously

deployed nodes.

The scheme has to work even without prior knowledge of

which nodes will come into

communication range of each other after deployment.

The scheme has to minimize both the

node's computational

overhead and the storage

requirements.


Pairwise Key Schemes

Pair

wis

e Ke

y P

re-d

istr

ibu

tio

n

Sch

emes

Probabilistic Key Pre-distribution

q-composite Random Key Pre-distribution

Polynomial Pool-Based Key Pre-distribution

Location Based Pairwise Key

Time Based Pairwise Key


Polynomial Pool-Based Key Pre-distribution

taken from D. Liu and P. Ning, “Establishing pairwise keys in distributed sensor networks", www.cs.iastate.edu/~cs610jw/CS610_LiuNing.ppt.


A dilemma









• Conclusions

3

Topology Control (TC) Basic Idea

Agenda


Topology Control (TC) Basic Idea• A topology control protocol can be defined as an iterative process that

dynamically reduces the initial topology of a wireless sensor network.

taken from Pedro Wightman, Miguel A. Labrador, ”Reducing the communication range or turning nodes off? An initial study for

wireless sensor networks”, A Research Article, 2011

Redundant sensed information.

Reduces :Radio Interference and collisions.


Topology Construction Phase

Initial Topology Reduced Topology




The A3 Protocol











• Conclusions

4

Proposed Schemes

Agenda


Contributions


Evaluations of Applying Pairwise Scheme on A3

Increase Number of Active Nodes Reduction in Networks Lifetime



The FPK Scheme

The proposed scheme has three phases:

Key Pre-distribution Setup Phase

Direct Shared Key Establishment Phase

Path Key EstablishmentPhase

The last two phases of the proposed scheme are the same as in the Donggang Liu & Peng Ningframework.

* We refer to the Donggang and Peng framework as the ”Basic

scheme” throughout this presentation.


The FPK Scheme Polynomial Pool Generation and keys assignment;

They have higher probability to have polynomial shared keys with every node

in network.

Are prohibited to assign shared keys with any other low energy level node.

They only allowed to get under overlapping probability a set of

polynomial shared keys with specific nodes, those having a higher energy

level over the same mean.

High

Energy

Level

Nodes

Low

Energy

Level

Nodes

Its key ring is

completed by a

set of polynomial

shared keys

A subset of its key

ring will have a

polynomial shared

keys that

proportion to the

number of high

energy level nodes


The FPK scheme needed only 8% of the nodes to be active while the basic scheme needed 10% of active nodes.

The FPK scheme exchanged a significant lesser number of messages compared to the basic scheme

The basic scheme consumes nearly about 4% of network’s energy higher than the FPK scheme

The FPK Scheme Evaluation

The simulation

experiments

show that…


The simulation

experiments

show that…

The FPK scheme optimized the network lifetime just about 17% over the basic scheme

The numbers of sensed data received by

the sink node are increased almost by 24%The numbers of topology maintenance recalls

are also increased nearly by 17%

As a consequence of extending

the network’s lifetime

The FPK Scheme Evaluation



The SOPK Scheme

• FPK scheme has a drawback.

• SOPK scheme is an upgraded version of the FPK scheme.

SOPK algorithm divided into two levels:

Obligatory Level Second Opportunity Level


The SOPK Scheme• Obligatory Level:

– Stage 1: Calculating the network’s energy mean.

– Stage 2: Keys assignment process.

– Each node has a level of energy less than the calculated mean, it divides its subset sinto two small subsets s’ and s”.

s’ subset collect polynomial shared keys with portion of other high energy level nodes.

S” subset (s” = s - s’) select of polynomial shared keys with portion of other low energy level nodes.

Stage 3: Calculate the energy mean for all of the powerful nodes.


The SOPK Scheme• Second Opportunity Level:

Then low energy level nodes reveal and use keys in their second subset s”.

After a time period, each of the previously remarked as high energy level nodes send back to the sink a message containing its remaining energy.

This project is funded by Structural Funds of the European Union and state budget of the Czech Republic30

SOPK Scheme

performance

Evaluations

The SOPK scheme optimized the lifetime of the WSN by almost 10% over the FPK scheme and around 24% over the basic scheme

The SOPK scheme raised the topology maintenance recalls above 10% over the previous proposed scheme and nearly above 23% over the basic scheme









• Conclusions

5

Conclusions

Agenda


Conclusions• The research represents two pairwise key pre-distribution scheme based on energy

observation as a pre-deployment knowledge.

• The two suggested schemes used such knowledge for differentiating between low andhigh energy levels nodes to constrain the shared keys assignment process, especially forlow energy level nodes.

– This improves the memory usage by limited capability nodes.

– Conserves their Energy.

– Reduces the complexity of the network’s messages.

– Reduces the amount of nodes competing to become part of the CDS.

• The small number of active nodes gained by both FPK and SOPK schemes compared tothe basic scheme yield an advantage for both schemes in a form of extending the lifetimeof the wireless sensor network.


Thank you

Mohamed Mostafa Fouad

[email protected]

Ostrava, Faculty of Electrical Engineering and Computer Science (9th FEB 2015)


Presentations & Public Speaking

A Pairwise Key Security Scheme Suits Topology Control Protocols, 2nd afro european workshop 9 feb 2015