一种可证安全的权益有向无环图共识机制

Provable secure consensus mechanism based on the directed acyclic graph and stake

给出了一个可证明安全性的共识机制。该机制主要由委员会协议和交易确认算法构成。委员会协议用于从共识节点中选出主动性强且权益较大的节点组成动态迭代的委员会,以并行处理区块链中用户产生的常规净交易。交易确认算法基于委员会成员所发出的链交易形成的有向无环图,通过有向无环图的直接和间接引用计算常规净交易被委员会成员确认的次数,当某个常规净交易被不少于委员会成员数量的2/3确认后,该常规净交易就被写入链中。在一些公认的假设下,证明了共识机制具有一致性和可结束性。进一步,初步搭建了基于该共识的区块链系统,测试了系统的性能,测试结果与理论估计相符。在部署16个委员会成员,交易批量为106时,测试系统的交易吞吐量约17000个交易每秒;对比目前较为高效的Honey Badger BFT共识协议,在相同配置下,该协议的交易吞吐量约2600个交易每秒,相差约6倍。

A provable secure consensus mechanism is proposed.The consensus mechanism consists of a committee agreement protocol and a transaction confirmation algorithm.Nodes with a strong initiative and more stakes are elected from consensus nodes through the committee agreement protocol,which form a dynamic and iterative committee to parallelly handle Normal Net Transactions(NNTs)generated by users in the blockchain.The transaction confirmation algorithm is based on a Directed Acyclic Graph(DAG)which is constructed from Chain Transactions(CTs)sent by committee members.The number of times that an NNT is confirmed by committee members is counted based on the direct and indirect references of a DAG.When an NNT is confirmed by at least two-thirds of the committee members,the transaction is welded in the chain.Under some accepted assumptions,the consensus mechanism is proven to have properties of consistency and termination.Further,a preliminarily blockchain system is built based on the consensus mechanism with the performance of the system tested.The test result is consistent with the theoretical estimation.When 16 committee members are deployed and the transaction batch is 106,the transaction throughput of the system is about 17000 transactions per second;Compared with the current HoneyBadger BFT consensus protocol,under the same configuration,the transaction throughput of the HoneyBadger BFT consensus protocol is about 2600 transactions per second,which is about 1/6 that of the system.