Hiroyuki Yoshino Naohiro Hayashibara Tomoya Enokido Makoto Takizawa Hierarchical Protocol for Byzantine Agreement in a Peer-to-Peer Overlay Network. 5-9 2005 conf/dexaw/2005 DEXA Workshops http://dx.doi.org/10.1109/DEXA.2005.106 db/conf/dexaw/dexaw2005.html#YoshinoHET05