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Wireless Sensor Network Security. Anuj Nagar CS 590. Introduction. Typical Wireless Sensor Network (WSN). Need for security. WSNs are becoming a cost effective, practical way to go about deploying sensor networks.
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Wireless Sensor Network Security Anuj Nagar CS 590
Introduction • Typical Wireless Sensor Network (WSN)
Need for security • WSNs are becoming a cost effective, practical way to go about deploying sensor networks. • Large range of applications from civilian to military purposes. • Pose different challenges as compared to traditional networks. Hence different mechanisms must be brought about. • Enormous research potential.
Main Aspects • Obstacles to WSN security. • Requirements of a Secure WSN. • Attacks. • Defensive Measures.
Obstacles to WSN Security • Very limited resources: • Limited memory and Storage space : A typical sensor has a 16 bit 8 Mhz CPU with 10K RAM, 48K Program Memory and 1M flash storage. • Power limitation
Obstacles to WSN Security -continued • Unreliable Communication : • Unreliable Transfer : Packet-based routing of the sensor network is connectionless hence unreliable. • Conflicts: Even if the channel is reliable, the communication may still be unreliable due to broadcast nature of WSN. • Latency: Multi-hop routing, network congestion and node processing can lead to greater latency in the network.
Obstacles to WSN Security –continued..again • Unattended Operation: • Exposure to Physical Attacks. • Managed Remotely: Hard to detect physical tampering. • No Central Management Point: Ideally a WSN should have no central management point. However, if the network is designed incorrectly it may lead to greater congestion.
Security Requirements • Shares some common points with traditional networks but also presents unique problems of its own. • Data confidentiality: Most important issue in any network. • Data integrity: Inability to modify data. • Data freshness: Ensures that no old messages have been replayed. Essential for shared key schemes.
Security Requirements - continued • Availability: Adjusting existing encryption algorithms to fit within a WSN has costs : • Additional computation consumes more energy. • Additional communication consumes more energy. • Threat of a single point failure if a central management point scheme is used.
Security Requirements – continued..again • Self Organization: A WSN is typically an ad hoc network which requires every node to be self organizing and self healing. • Time Synchronization: e.g. to calculate the end to end delay time of packets between nodes. • Secure localization: Ability to accurately and automatically locate each sensor in the network. • Authentication
Attacks • Vulnerable to a multitude of attacks such as DoS, traffic analysis, privacy violation, physical attacks and so on. • DoS: Jamming a node or set of nodes by transmission of a radio signal that interferes with radio frequencies being used. • Violate the communication protocol thus depleting valuable battery life.
More attacks • Sybil attack: • Defined as a “malicious device illegitimately taking on multiple identities.” • Originally used against peer to peer networks but may also be used to disrupt routing algorithms, data aggregation etc. • Traffic Analysis Attacks: Take over the base station/nodes closest to base station.
Yet more attacks • Node replication attacks. • Attacks against privacy. • Physical attacks.
Defensive Measures • Key Establishment. • Secure Broadcasting and Multicasting. • More efficient routing protocols. • Intrusion Detection.
Conclusion • Emerging field in a traditional world of computer security. • A vast amount of research work is being conducted in this area. • Possible thesis ideas: Working on key distribution schemes, modifying existing encryption algorithms, working on the IDS side of things.
References [1] I. F. Akyildiz, W. Su, Y. Sankarasubramaniam, and E. Cayirci. A survey on sensor networks. IEEE Communications Magazine, 40(8):102–114, August 2002. [2] P. Albers and O. Camp. Security in ad hoc networks: A general intrusion detection architecture enhancing trust based approaches. In First International Workshop on Wireless Information Systems, 4th International Conference on Enterprise Information Systems, 2002. [3] R. Anderson and M. Kuhn. Tamper resistance - a cautionary note. In The Second USENIX Workshop on Electronic Commerce Proceedings, Oakland, California, 1996. [4] R. Anderson and M. Kuhn. Low cost attacks on tamper resistant devices. In IWSP: International Workshop on Security Protocols, LNCS, 1997. [5] T. Aura, P. Nikander, and J. Leiwo. Dos-resistant authentication with client puzzles. In Revised Papers from the 8th International Workshop on Security Protocols, pages 170–177. Springer-Verlag, 2001.