Providing Security Services for Mobile Ad Hoc Networks

This dissertation, "Providing Security Services for Mobile Ad Hoc Networks" by Ying, Dong, 董穎, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled Providing Security Services for Mobile Ad Hoc Networks Submitted by Dong Ying for the degree of Doctor of Philosophy at The University of Hong Kong in November 2007 Withtheincreasingpopularityofmobileadhocnetworks(MANETs), secu- rity has become a primary concern due to the necessity of protecting the com- munications between the mobile nodes. MANETs are characterized by open wireless media, node mobility, network dynamics, and lack of infrastructure, which make them susceptible to malicious attacks. The unique characteristics of MANETs pose a number of nontrivial challenges to the security design. Many studies have been conducted recently on secure communications in MANETs. Key management is the most critical element of secure commu- nications because it is the cornerstone of many security services. Public key infrastructure (PKI) has been proposed to be applied to MANETs due to its eciency in key management. However, the traditional PKI, which relies on a central trust-by-all server, called certicate authority (CA), for key manage- ment, cannot be used directly for MANETs since the single CA architecturesuers from the single point of failure problem. To resolve this problem, dis- tributed CA approaches are proposed, in which the functionality of a single CA is distributed to multiple CAs by secret sharing and threshold cryptography. In this study, we propose a cluster-based architecture to provide distributed certicate authority services for key management for MANETs to improve the eciency of the distributed CA services. We also propose a new framework to provide dynamic distributed CA services to balance the requirements of service availability and security level. Anonymity is an important security service in many security sensitive ap- plications. However, the open wireless medium of MANETs makes it easy for adversaries to launch trac analysis attack against the routing information embedded in the routing messages and data packets to detect the trac pat- tern of the communications and identify important nodes, thereby obtaining sensitive information of the system. In order to thwart trac analysis attacks, anonymous routing schemes which enable anonymous communications are re- quired. However, this is an area in which little research has been done, and in this study we propose an anonymous routing protocol to establish multiple anonymous routes with the identities of nodes on a route being hidden, by applying the Die-Hellman key agreement scheme and the Bloom lter. Our scheme provides strongly anonymous communications in MANETs. Sign: DOI: 10.5353/th_b3955711 Subjects: Mobile communication systems - Security measures Wireless communication systems - Security measures Computer networks - Security measures