The weighted Byzantine Agreement Problem

dc.contributor.advisorGarg, Vijay K. (Vijay Kumar), 1963-en
dc.contributor.committeeMemberEvans, Brian L.en
dc.creatorBridgman, John Francisen
dc.date.accessioned2012-08-13T14:18:27Zen
dc.date.accessioned2017-05-11T22:26:48Z
dc.date.available2012-08-13T14:18:27Zen
dc.date.available2017-05-11T22:26:48Z
dc.date.issued2012-05en
dc.date.submittedMay 2012en
dc.date.updated2012-08-13T14:18:33Zen
dc.descriptiontexten
dc.description.abstractThis report presents a weighted version of the Byzantine Agreement Problem and its solution under various conditions. In this version, each machine is assigned a weight depending on the application. Instead of assuming that at most $f$ out of $N$ machines fail, the algorithm assumes that the total weight of the machines that fail is at most $\rho < 1/3.$ When each machine has weight $1/N,$ this problem reduces to the standard Byzantine Generals Agreement Problem. By choosing weights appropriately, the weighted Byzantine Agreement Problem can be applied to situations where a subset of processes are more trusted. By using weights, the system can reach consensus in the presence of Byzantine failures, even when more than $N/3$ processes fail, so long as the total weight of the failed processes is less than $1/3.$ Some properties of the Weighted Byzantine Agreement algorithms when the weight vectors are not the same at every process are discussed. Also, a method to update the weights of the processes after execution of the weighted Byzantine Agreement is given. The update method guarantees that the weight of any correct process is never reduced and the weight of any faulty process, suspected by correct processes whose total weight is at least $1/4,$ is reduced to $0$ for future instances. A short discussion of some weight assignment strategies is also given.en
dc.description.departmentElectrical and Computer Engineeringen
dc.format.mimetypeapplication/pdfen
dc.identifier.slug2152/ETD-UT-2012-05-5616en
dc.identifier.urihttp://hdl.handle.net/2152/ETD-UT-2012-05-5616en
dc.language.isoengen
dc.subjectByzantine Agreementen
dc.subjectAgreementen
dc.subjectDistributed systemsen
dc.subjectApproximate agreementen
dc.subjectReliabilityen
dc.titleThe weighted Byzantine Agreement Problemen
dc.type.genrethesisen

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