@inproceedings{oai:nitech.repo.nii.ac.jp:00005909, author = {Banu, Nazreen and Izumi, Taisuke and Wada, Koichi}, book = {Proceedings of the 2010 IEEE/IFIP International Conference on Dependable Systems and Networks (DSN)}, month = {Apr}, note = {application/pdf, It is known that Byzantine consensus algorithms guarantee one-step decision only in favorablesituations (e.g. when all processes propose the same value) and no one-step algorithm can support two-step decision. This paper presents DEX, a novel one-step Byzantine algorithm that circumvents theseimpossibilities using the condition-based approach. Algorithm DEX has two distinguished features:Adaptiveness and Double-expedition property. Adaptiveness makes it sensitive to only actual numberof failures so that it provides fast termination for more number of inputs when there are fewer failures (acommon case in practice). The double-expedition property facilitates two-step decision in addition toone-step decision by running two condition-based mechanisms in parallel. To the best of our knowledge,double-expedition property is the new concept introduced by this paper, and DEX is the  ̄rst algorithmhaving such a feature. Although DEX takes four steps at worst in well-behaved runs while existingone-step algorithms take only three, it is expected to work efficiently because the worst-case does notoccur so often in practice., This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessible.Proceedings on The 40th Annual IEEE/IFIP International Conference on Dependable Systems and Networks}, pages = {373--382}, publisher = {Institute of Electrical and Electronics Engineers Computer Society}, title = {Doubly-Expedited One-Step Byzantine Consensus}, year = {2010} }