ISSN : 1796-2056
Volume : 3    Issue : 6    Date : June 2008

Analysis of Proposed Key Establishment Protocols in Multi–Tiered Sensor Networks
Kalvinder Singh and Vallipuram Muthukkumarasamy
Page(s): 13-28
Full Text:
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Wireless sensor networks provide solutions to a range of monitoring problems. However, they
introduce a new set of problems mainly due to small memories, weak processors, limited energy
and small packet size. Thus only a very few conventional protocols can readily be used in sensor
networks. This paper closely examines the currently available key distributions protocols, their
strengths and limitations. The performance of these protocols under different scenarios are
thoroughly investigated using theoretical analysis and using a simulation study with TinyOS. First a
number of single server protocols were proposed and their performance was analysed. Then we
propose a new set of multi–server key distribution protocols, where base stations (or controller
nodes) are untrusted. The proposed solutions replicate the authentication server such that a group
of malicious and colluding servers cannot compromise security or disrupt service. A detailed
comparison of the performance of the proposed protocols with that of other available protocols
show the advantages of our protocols. We show that the proposed multiple server authentication
protocols will only have O(n) complexity, where n is the number of authentication servers. The
protocols use information from the sensor nodes and the servers to generate a new key, and do not
solely rely on the sensor nodes to generate good random numbers. The proposed protocols
guarantee that the new key is fresh and that the communicating nodes use the same key.

Index Terms
wireless sensors, network security, key distribution, cryptography, performance