CS 265 PROJECTCS 265 PROJECT

Secure Routing in Wireless Sensor Networks : Directed Diffusion a

study

Ajay Kalambur

OutlineOutline

IntroductionDirected DiffusionAttacksCountermeasures

IntroductionIntroduction

Array of sensors deployed to monitor real time events

The concepts derived from adhoc networks

Much more energy starved than adhoc networks

Sensor nodes limited battery and memory

Introduction(contd)Introduction(contd)

Scalability Self Organization Data Collection , aggregation and

processing All protocols must be designed such

that they are energy efficient

NETWORK ARCHITECTURE(My project)NETWORK ARCHITECTURE(My project)

CLUSTERS OF SENSOR NODES

LOCAL BASESTATION

LOCAL BASESTATION

Sensor Node ArchitectureSensor Node Architecture

Power Unit(Battery)

Location finding system

TransceiverSensor ADC

SensingUnit

ProcessingUnit

Processor

Storage

Directed DiffusionDirected Diffusion

Data centric , interest-based routing protocol

Base station or sink node disseminates interest

Gradient established in opposite direction for data flow

Positive and Negative Reinforcements possible

Interests also stored in interest cache at each node

Diffusion (in molecules)Diffusion (in molecules)

THE PICTURETHE PICTURE

Example Interest from Base station Example Interest from Base station or sink nodeor sink node Type=toxin Interval=1s //send every second Duration=50 seconds //for next 50 seconds Rect=[-100,100,250,300]

Response from sensor node Response from sensor node detecting the eventdetecting the event Type=toxin Instance=mercury Location=[120,225] Intensity=0.6 Confidence=0.7 Timestamp=03:14:45

Attacks on Directed DiffusionAttacks on Directed Diffusion

Denial of Service -jammingModification and spoofing of

routing infoDropping or selective

forwarding of data

Denial of ServiceDenial of Service

Modification and Spoofing of Modification and Spoofing of routing inforouting info

Dropping or selective forwarding Dropping or selective forwarding of dataof data Previous attack enables malicious node to

get into path of data flow The spoofed positive and negative

reinforcements and spoofed data, Selective forwarding is trivial to achieve

Dropping all packets- similar to node being non existent.

Selective forwarding is a more dangerous security issue

COUNTERMEASURESCOUNTERMEASURES

Link layer security with each node sharing a unique key with base station

Efficient Symmetric key cryptographic schemes needed

Public key cryptography not possible Defense against internal attacks is very

challenging Routing protocol needs to be designed

carefully

ReferencesReferences

[1] C. Intanagonwiwat, R. Govindan, and D. Estrin, “Directed Diffusion: A Scalable and Robust Communication paradigm for Sensor Networks,” Proc. ACM MobiCom, Boston, MA, pp. 42-49, 2000.

[2]. Chris Karlof and David Wagner, “Secure Routing in Wireless Sensor Networks,” Adhoc Networks, Volume1, Issues 2-3, pp: 293-315, September 2003.