Routing Protocol for Wireless Sensor Network in Hostile

Environments

PhD Student : Kashif SagharSupervisors:

William HendersonDavid Kendall

Outline

• Wireless Sensor Networks (WSN) and Routing

• Formal Modelling

• Challenges & Security Issues in WSN

• Research Aim

• Research Method

• Progress

WIRELESS SENSOR NETWORK (WSN)

WSN COMMUNICATION ARCHITECTURE

Physical Layer

Data Link (MAC) Layer

Network Layer

Transport Layer

Application Layer

Routing

WHY WSN ARE DIFFERENT?

• Fault Tolerance• Scalability• Density• Hardware Constraints• Cost• Power Consumption• WSN Topology

ROUTING IN WSN

• Cost• Energy-efficiency• Latency• Mobility• Distribution density• Scalability• Quality of Service (QoS)

SECURITY ISSUES IN WSN

• Broadcast Nature

• Limited Resources

• Unattended

• Hostile Environment

AIM AND OBJECTIVES

• AIM/Purpose– "Attacks on Wireless Sensor Networks, having limited resources,

can be successfully resisted at the Network Layer."

• Primary Assumptions– Confidentiality and Authentication Scheme is present at Link

Layer– Sink is a highly resourced node– Nodes do not have any special hardware– The approximate time to compromise a node is known in

advance– Nodes can be placed by any means (Random, Regular)– Attacker is very Powerful

WSN ATTACKS CONSIDERED

• Wormhole– Two colluding nodes– A node at one end of the wormhole advertises high quality link to the

base station– Another node at the other end receives the attracted packets– Two Laptops or Normal Nodes

• Black hole – Selective Forwarding– Fail Encryption or via Wormhole

• Sink hole– Node attract all traffic around by making itself attractive to all nodes with

in range e.g. Laptop– Fail Encryption or via Wormhole

• Insider Attack– Get into network by node compromise or false node

LIST OF SOME WSN ATTACKS

• Spoofing• False Injection or Path-base Denial of Service• Black hole or Selective forwarding• Sinkhole attacks• Sybil attacks• Wormholes• Jamming• Eavesdropping• Traffic Analysis Attack• Insider Attack (Compromised Node)• False Node and malicious data• Rushing Attack• Stealthy Attack• Hello Flood Attack

LITERATURE REVIEW ANALYSIS

69.3%

14.9%

5.9%

4.0%

2.5%

3.5%

0% 10% 20% 30% 40% 50% 60% 70%

CryptographicTechniques

M ultiple-pathProtocols

Overhear Neighbour

Topology M apping

Specialized Hardware

Reward Protocols

Sche

me Us

ed

Percentage

6.1%4.0%3.2%

4.9%

5.3%

0.8%1.6%0.4%

2.4%

5.3%

20.6%

45.3%

Spoofing

False Injection

Black hole

Sinkhole attacks

Sybil attacks

Wormhole attack

Jamming

Traffic analysis Attack

Rushing Attack

Stealthy Attack

Hello Flood Attack

Insider Attack

88.5%

2.7%1.8%

1.8% 1.8% 2.7%

1 Attack

2 Attacks

3 Attacks

4 Attacks

5 Attacks

6 or M ore Attacks

DESIGN PHASES

SETUP PHASE

OPERATIONAL PHASE

ATTACK PREVENTION

TECHNIQUES AVAILABLE

• Formal Modelling• WSN Simulation• Empirical Testing

FORMAL MODELLING

• Assumptions become clear• Can check Best cases and Worst Cases easily• Inform about boundaries of protocol behaviour• Liveliness and Safety properties• Rarely used in analysis of previous protocols• Main Advantages over Simulation and Empirical Testing:

– No need to build a prototype of the system– Able to verify the system against every single execution trace (Hidden

Errors)• Shortcomings

– High Resources Required for detailed model– Scalability, Density, Topology– Subset of Model can be checked– Expertise Required– Uncertainty

UPPAL MODEL OF DESIGN (SETUP)

VERIFICATION USING UPPAAL

• Theorem1: Model never deadlocks

• Theorem2: All nodes get the correct level

• Theorem3: The levels of nodes are not changed once all nodes get the correct

• Theorem4: A node in INIT mode means it has not yet been assigned a level

• Theorem5: A node always gets a level and gets out of INIT mode

MESSAGE SEQUENCE DIAGRAM

Node1Sink

ASK

Node2

ASK

Node3 Node4

Node alwayssends ASKbeacon whenit startsASK ASK

ASK ASK

ASSIGN

LOUDLOUD

Node 1 hasbeen assigned Level 2 by Sink

ASK ASK

ASSIGN

Node 1 onreceiving ASKsends ASSIGN

LOUDLOUD

Node 2 observesneighbours for some time and thenannounce its level

ASK ASK

ASSIGN

LOUD LOUD

ASK

ASSIGN

LOUD

Node1Sink Node2 Node3 Node4

Node 3 has detected an Event !!!

Node 3 receivedACCEPT from bothNeighbours

FORWARDFORWARD

ACCEPT ACCEPT

FORWARDFORWARD

DATA

ACCEPT

DATA

ACK

ACK

ACK

As Node 1 is atLevel next to Sinkit do not send FORWARD

Sink sends ACKwhich is propagatedback to source node

SELECT

DATA DATA

SELECT

Data is only Recby Node2 whichwas selected

SIMULATION

• Level of simulator (High, Low, Bit Level)• Usual Workability• Scalability• Effect of Topology• Effect of Density• Vary environment conditions• Shortcomings

– Ideal cases are checked only– Hidden Errors

Average Number of Beacons per Node (500 Nodes)

0.0

10.0

20.0

30.0

40.0

Range (m)

Avera

ge N

um

ber

of

Beaco

ns/N

od

e

Ask Assign Loud

Ask 11.6 6.3 4.8 4.5 4.7

Assign 2.6 7.2 16.5 26.0 26.6

Loud 2.1 3.0 3.7 4.3 3.8

100 200 300 400 500

Average Number of Beacons per Node (100 Nodes)

0.0

10.0

20.0

30.0

40.0

Range (m)

Averag

e N

um

ber o

f

Beaco

ns/N

od

e

Ask Assign Loud

Ask 5.7 3.4 2.8 2.8 3.2 3.7 4.6 5.6 8.0 9.2 10.2

Assign 2.3 4.9 11.3 13.7 16.6 18.7 23.0 29.6 34.8 43.2 46.2

Loud 2.1 2.5 3.3 3.2 3.2 3.1 3.0 2.9 2.9 3.0 3.0

100 200 300 400 500 600 700 800 900 1000 All

Effect of Density on Setup Time (100 Node Network)

0.0

10.0

20.0

30.0

40.0

Range (m)

Tim

e (

Seco

nd

s)

Average

Max

Min

Average 14.6 11.4 11.8 12.2 12.2 13.6 14.2 16.8 20.6 23.8 27.3

Max 16.0 12.0 13.0 13.0 13.0 14.0 15.0 18.0 22.0 25.0 29.0

Min 14.0 11.0 11.0 11.0 12.0 13.0 13.0 16.0 20.0 22.0 26.0

100 200 300 400 500 600 700 800 900 1000 All

Effect of Density on Setup Time (1000 Node Network)

0.0

10.0

20.0

30.0

40.0

50.0

Range (m)

Tim

e (

Seco

nd

s)

Average

Max

Min

Average 36.0 25.8 24.4 24.8 21.0

Max 36.0 32.0 26.0 26.0 22.0

Min 36.0 20.0 22.0 23.0 20.0

100 200 300 400 500

Effect of Density on Setup Time (500 Node Network)

0.0

10.0

20.0

30.0

40.0

50.0

Range (m)

Tim

e (

Se

co

nd

s)

Average

Max

Min

Average 28.2 22.2 17.6 20.4 18.6

Max 33.0 28.0 19.0 23.0 22.0

Min 26.0 16.0 17.0 18.0 17.0

100 200 300 400 500

CURRENT AND FUTURE WORK

• Current Work– Formal specifications of design

• Future Work– Formal Model and Verification– Simulation of complete protocol– Simulation of Attacks

• Additional/Optional Work– Implementation in Real Hardware

Questions