Efficient Pairwise Key Establishment Scheme Based on Random Pre-Distribution Keys in Wireless Sensor Networks

Source: Lecture Notes in Computer Science, Vol. 6018, pp. 291-304, 2010.Authors: Hao Wang, Jian Yang, Ping Wang, and Pu TuPresenter: Hsing-Lei WangDate: 2011/02/18

Outline•Introduction•Cluster-Based Deployment Model•Efficient Pairwise Key Establishment and

Management•Performance Analysis•Conclusion•Comments

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Introduction•Main contributions:

▫Propose the new cluster-based model of the network topology

▫Present the pairwise key establishment scheme

•Advantages:▫Better connectivity and security▫Lower communication and computational

overhead▫More scalable and flexible network size

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Cluster-Based Deployment Model•Notation (1)

▫P: key pool▫|P|: size of key pool▫M: sub key pool▫|M|: size of sub key pool▫m: number of keys in each node’s key ring▫n: network size▫t: number of clusters▫Ni: Node identifier

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Cluster-Based Deployment Model•Notation (2)

▫r: number of nodes in a cluster▫p: probability▫Bu: the broadcasting message of node u▫kuv: pairwise key shared by node u and v▫Nu: random value generated by node u▫k_ID_uvw1: common key’s ID of node u, v ▫Ekuc

{M}: cipher text of message M encrypted by key kuc

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Cluster-Based Deployment Model

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The Network Topology of the Cluster-Based Deployment Model

Key Pool P

Sub-Key Pool M

Cluster Cluster

ClusterCluster

N1 N2 N

N

N

C-Head

m

m

mm

m

mm

m

m

Efficient Pairwise Key Establishment and Management •Establishment of the Pairwise Keys

Directly

•Establishment of the Pairwise Keys via Intermediate Nodes

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Establishment of the Pairwise keys Directly (1/3)•Node u find the common keys by

broadcasting a message to its neighbor nodes

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, _ 1, _ 2,..., _u uB u N k ID k ID k IDm

u

uB

uB

uB

uB

Establishment of the Pairwise keys Directly (2/3)•Assume a node v received the message, it

will compare all the node u keys’ ID with its own keys’ ID, then reply their common keys’ ID to the node u

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v u , _ _ 1, _ _ 2,..., _ _uM v N k ID uv k ID uv k ID uvw

Establishment of the Pairwise keys Directly (3/3)• The common keys will be stored in a form as

Table 1• They take the first common key as their pairwise

key

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Establishment of the Pairwise Keys

via Intermediate Nodes (1/4)

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•If node v found that there is no common key with node u, it then returns a message to u

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Establishment of the Pairwise Keys

via Intermediate Nodes (2/4)

, ,u vM v N Nv u

•Node u receives the message, stores Nv, and selects node a, c to forward the key’s materials to node v

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Establishment of the Pairwise Keys

via Intermediate Nodes (3/4)

1, |uak uM u E v N

2, |uck uM u E v N

u

a

c

Establishment of the Pairwise Keys

via Intermediate Nodes (4/4)•If node a, c have the pairwise keys with node v, they transmit the messages to node v.

•The node u and node v can calculate a new pairwise key:

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1 2uv v u uk N N N v u

Performance Analysis•Network Connectivity (1/2)

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|P|=10,000

Performance Analysis•Network Connectivity (2/2)

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Performance Analysis•Security Analysis

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Conclusion•Compared to the EG Scheme and the

Chan et al. Scheme, this scheme has some properties:▫Better network connectivity and resiliency▫Much more scalable and flexible for

network size▫Lower computational and communication

overhead

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Comments•The cluster head management

mechanisms should be described•The analysis of the computational and

communication overhead should show the comparison of the overhead by numbers

•The authors have not compare their scheme to the EG scheme and Chan et al. scheme in network connectivity

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