Security for Wireless Sensor Networks (eBook)

Preface 7
Contents 9
1 Introduction 12
1.1 Wireless Sensor Network 12
1.2 Design Challenges 13
1.3 Security Issues in Sensor Networks 14
1.4 Orgnization of the Book 18
2 Broadcast Authentication 20
2.1 pTESLA Broadcast Authentication 21
2.2 Multi-Level pTESLA 23
2.3 Tree-Based pTESLA 53
2.4 Summary 68
3 Pairwise Key Establishment 70
3.1 Key Pre-Distribution Techniques in Sensor Networks 71
3.2 Polynomial Pool-Based Key Pre-Distribution 74
3.3 Key Pre-Distribution Using Random Subset Assignment 78
3.4 Hypercube-based Key Pre-Distribution 88
3.5 Implement at ion and Evaluation 103
3.6 Summary 107
4 Improving Pairwise Key Establishment Using Deployment Knowledge 110
4.1 Improving Key Pre-Distribution with Prior Deployment Knowledge 111
4.2 Improving Key Pre-Distribution with Post Deployment Knowledge 131
4.3 Improving Key Pre-Distribution with Group Deployment Knowledge 140
4.4 Summary 159
5 Secure Localization 160
5.1 Localization in Sensor Networks 161
5.2 Pitfalls of Current Localization Schemes under Attacks 162
5.3 Attack-Resistant Location Estimation 164
5.4 A Detector for Malicious Beacon Nodes 186
5.5 Summary 205
6 Summary and Future Work 208
6.1 Summary 208
6.2 Future Work 209
References 212
Index 218

1.3.2 Pairwise Key Establishment (p. 5)
Pairwise key establishment is another important fundamental security service. It enables sensor nodes to communicate securely with each other using cryptographic techniques. The main problem here is to establish a secure key shared between two communicating sensor nodes. However, due to the resource con- straints on sensor nodes, it is not feasible for them to use traditional pairwise key establishment techniques such as public key cryptography and key distribution center (KDC).

Instead of the above two techniques, sensor nodes may establish keys between each other through key pre-distribution , where keying materials are pre-distributed to sensor nodes before deployment. As two extreme cases, one may setup a global key among the network so that two sensor nodes can establish a key based on this key, or one may assign each sensor node a unique random key with each of the other nodes. However, the former is vulnerable to the compromise of a single node, and the latter introduces huge storage overhead at sensor nodes.

Eschenauer and Gligor proposed a probabilistic key pre-distribution scheme recently for pairwise key establishment [20]. The main idea is to let each sensor node randomly pick a set of keys from a key pool before the deployment so that any two sensor nodes have a certain probability to share at least one common key. Chan et al. further extended this idea and developed two key pre-distribution techniques: a q-composite key pre-distribution scheme and a random pairwise keys scheme [12]. The q-composite key pre-distribution also uses a key pool but requires that two nodes compute a pairwise key from at least q pre-distributed keys that they share. The random pairwise keys scheme randomly picks pairs of sensor nodes and assigns each pair a unique random key. Both schemes improve the security over the basic probabilistic key pre-distribution scheme.

However, the pairwise key establishment problem is still not fully solved. For the basic probabilistic and the q-composite key pre-distribution schemes, as the number of compromised nodes increases, the fraction of affected pairwise keys increases quickly. As a result, a small number of compromised nodes may disclose a large fraction of pairwise keys. Though the random pairwise keys scheme does not suffer from the above security problem, given a memory constraint, the network size is strictly limited by the desired probability that two sensor nodes share a pairwise key, the memory available for keys on sensor nodes, and the number of neighbor nodes that a sensor node can communicate with. Techniques to address this problem are provided Chapter 3 and Chapter 4.

1.3.3 Security in Localization
Sensors' locations play a critical role in many sensor network applications. Not only do applications such as environment monitoring and target tracking require sensors' location information to fulfill their tasks, but several fundamental techniques developed for wireless sensor networks also require sensor nodes' locations. For example, in geographical routing protocols (e.g., GPSR [35] and GEAR [80]), sensor nodes make routing decisions at least partially based on their own and their neighbors' locations.