Summary: | 碩士 === 國立清華大學 === 資訊工程學系 === 93 === Wireless sensor networks consist of many low-cost sensor nodes which have sensing capability with limited computation, memory and energy resources. Sensor nodes are mainly used to collect data by sensing the environment, process it locally, and send information back to a more powerful base station. Due to the limited resources on sensor nodes, asymmetric cryptographic algorithms and high cost operations like the modular exponentiation operation are not appropriate for providing security.
Many applications of wireless sensor networks, e.g. environmental monitoring, are based upon a group communication model. The base station needs to securely deliver messages to a large number of authorized sensor nodes. The establishment of a group key for encrypting group communication is therefore becoming an important concern to prevent an attacker from eavesdropping communications in wireless sensor networks.
To support secure group communications in resource constrained wireless sensor networks, we propose an efficient and scalable key management protocol which only uses symmetric cryptographic algorithms and low cost operations. Our protocol can achieve current, forward and backward secrecy, and even if an attacker compromises a sensor node and a cluster head, it can still not cause the compromise of the entire group. Furthermore, for scalability, the communication and computation cost of each component for group key renewing can be kept independent of the group size when the group membership changes. Our protocol provides better efficiency and is more suitable than the previous group key management protocols for wireless sensor networks.
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