Each round 21 witnesses are selected to create and sign
blocks of transactions. Twenty (20) of these witnesses are selected by approval voting and one is
timeshared by every witness that didn’t make it into the top 20 proportional to their total votes. The 21
active witnesses are shuffled every round to prevent any one witness from constantly ignoring blocks
produced by the same witness placed before. Any witness who misses a block and hasn't produced in the
last 24 hours will be disabled until they update their block signing key
也就是说攻击11个节点就能导致整个EOS网络没有能力继续处理事务了，直到新的11个主节点被选出来。总感觉哪里不对，按说设计者不可能没考虑这个因素啊
目前steemit也是采取的DPos的共识方式，一共21个节点，每次21个区块记录后，要重新洗牌。EOS, BITSHARES, STEEM的共识机制都一样的。这些节点的矿工（witness）都是选出来的，排着队往上冲，要被选成排名靠前的矿工是很不容易的事情，或许这种机制导致要攻击起来不容易吧，steemit和bitshares就是试验田。
Each round 21 witnesses are selected to create and sign
blocks of transactions. Twenty (20) of these witnesses are selected by approval voting and one is
timeshared by every witness that didn’t make it into the top 20 proportional to their total votes. The 21
active witnesses are shuffled every round to prevent any one witness from constantly ignoring blocks
produced by the same witness placed before. Any witness who misses a block and hasn't produced in the
last 24 hours will be disabled until they update their block signing key