1-1hit |
Feng BAO Yoshihide IGARASHI Keiko KATANO
We study all-to-all broadcasting in hypercubes with randomly distributed Byzantine faults. We construct an efficient broadcasting scheme BC1-n-cube running on the n-dimensional hypercube (n-cube for short) in 2n rounds, where for communication by each node of the n-cube, only one of its links is used in each round. The scheme BC1-n-cube can tolerate (n-1)/2 Byzantine faults of nodes and/or links in the worst case. If there are exactly f Byzantine faulty nodes randomly distributed in the n-cabe, BC1-n-cube succeeds with a probability higher than 1(64nf/2n) n/2. In other words, if 1/(64nk) of all the nodes(i.e., 2n/(64nk) nodes) fail in Byzantine manner randomly in the n-cube, then the scheme succeeds with a probability higher than 1kn/2. We also consider the case where all nodes are faultless but links may fail randomly in the n-cube. Broadcasting by BC1-n-cube is successful with a probability hig her than 1kn/2 provided that not more than 1/(64(n1)k) of all the links in the n-cube fail in Byzantine manner randomly. For the case where only links may fail, we give another broadcasting scheme BC2-n-cube which runs in 2n2 rounds. Broadcasting by BC2-n-cube is successful with a high probability if the number of Byzantine faulty links randomly distributed in the n-cube is not more than a constant fraction of the total number of links. That is, it succeeds with a probability higher than 1nkn/2 if 1/(48k) of all the links in the n-cube fail randomly in Byzantine manner.