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CS 265 PROJECT. Secure Routing in Wireless Sensor Networks : Directed Diffusion a study Ajay Kalambur. Outline. Introduction Directed Diffusion Attacks Countermeasures. Introduction. Array of sensors deployed to monitor real time events The concepts derived from adhoc networks
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CS 265 PROJECT Secure Routing in Wireless Sensor Networks : Directed Diffusion a study Ajay Kalambur
Outline • Introduction • Directed Diffusion • Attacks • Countermeasures
Introduction • 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) • Scalability • Self Organization • Data Collection , aggregation and processing • All protocols must be designed such that they are energy efficient
Sensor Node Architecture Location finding system Sensing Unit Processing Unit Processor Transceiver Sensor ADC Storage Power Unit(Battery)
Directed 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
Example Interest from Base station or 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 detecting the event • Type=toxin • Instance=mercury • Location=[120,225] • Intensity=0.6 • Confidence=0.7 • Timestamp=03:14:45
Attacks on Directed Diffusion • Denial of Service -jamming • Modification and spoofing of routing info • Dropping or selective forwarding of data
Dropping or selective forwarding of 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
COUNTERMEASURES • 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
References • [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.