Decentralization is a key indicator for the evaluation of public blockchains. In the past, there have been very few studies on measuring and comparing the actual level of decentralization between Proof-of-Work (PoW) blockchains and blockchains with other consensus protocols. This paper presents a new comparison study of the level of decentralization in Bitcoin and Steem, a prominent Delegated-Proof-of-Stake (DPoS) blockchain. Our study particularly focuses on analysing the power that decides the creators of blocks in the blockchain. In Bitcoin, miners with higher computational power generate more blocks. In contrast, blocks in Steem are equally generated by witnesses while witnesses are periodically elected by stakeholders with different voting power weighted by invested stake. We analyze the process of stake-weighted election of witnesses in DPoS and measure the actual stake invested by each stakeholder in Steem. We then compute the Shannon entropy of the distribution of computational power among miners in Bitcoin and the distribution of invested stake among stakeholders in Steem. Our analyses reveal that neither Bitcoin nor Steem is dominantly better than the other with respect to decentralization. Compared with Steem, Bitcoin tends to be more decentralized among top miners but less decentralized in general. Our study is designed to provide insights into the current state of the degree of decentralization in DPoS and PoW blockchains. We believe that the methodologies and findings in this paper can facilitate future studies of decentralization in other blockchain systems employing different consensus protocols.
翻译:权力下放是评估公共链条的关键指标。在过去,关于衡量和比较工作证明(PoW)链条和障碍与其他协商一致协议之间的实际权力下放水平的研究很少。本文件对Bitcoin和Steem(一个著名的权力下放代表)的权力下放程度进行了新的比较研究。我们的研究特别侧重于分析决定链条中各链条的创建者的权力。在Bitcoin,计算能力较高的矿工产生更多的障碍。相比之下,Steem的路障同样由证人产生,而证人则由拥有不同投票权的利益攸关方定期选举,按投资利益加权。我们分析了DPoS中证人的定额选举过程,并测量了每个利益攸关方在Steem中的实际利益。我们随后比较了Bitcoin矿工之间计算能力分配的香农通气,以及Steem中投资协议的分布。我们的分析表明,Bitcoin和Steem的路障都是由拥有不同投票权的利益攸关方定期选举产生的,而Steem在进行这种权力下放的研究中比其他权力下放的程度要低。我们更相信,在进行这种分散化研究时,我们更倾向于采用其他的方法。