Qi Dong

Graduation Semester and Year




Document Type


Degree Name

Doctor of Philosophy in Computer Science


Computer Science and Engineering

First Advisor

Donggang Liu


The unique features of wireless networks lead to many attractive applications in both military and civilian operations. Wireles networking devices usually use batteries as power supply, which requires all the operations to be as efficient as possible. Since the resources such as the battery energy and wireless communication channels are critical in wireless networks, the attacker my try to disable the system operation by launching denial of service (DoS) attacks. Specifically, the attacker prevents the system from working by using up or blocking the limited resources.This dissertation includes three studies on security mechanisms to combat DoS attacks using lightweight key management schemes. The first study introduces a novel pairwise key establishment technique. It can achieve both high resilience to node compromises and high efficiency by using a small number of additional sensor nodes. This work provides the basic cryptographic building blocks for other techniques proposed in this dissertation.The second study presents two filtering techniques, a group-based filter and a key chain-based filter, to handle DoS attacks when digital signatures are used for broadcast authentication in sensor networks. Both methods are efficient for resource-constrained sensor networks and can significantly reduce the number of unnecessary signature verifications that a sensor node has to perform.The third study introduces two techniques for jamming-resistant broadcast systems, partial channel sharing and unpredictable channel assignment. Both schemes can significantly reduce the extra communication cost. The analytic and simulation results show that the proposed approaches greatly push the limit of jamming-resistant broadcast towards optimal.


Computer Sciences | Physical Sciences and Mathematics


Degree granted by The University of Texas at Arlington