Blockchain leader-based protocols elect leaders for proposing the next block of transactions. Proposed blocks need to pass a validation routine in order to be added to the blockchain. Proposers may prioritize certain transactions based on their fees or accounts, which enables attackers to gain profits through block building, while simultaneously causing negative impacts on other users. A fair block selection follows a random selection of pending transactions among those that a proposer is aware of. We propose CFTO, a protocol that aims at encouraging fair block selection in a leader-based blockchain network while taking into account real network conditions, such as the network’s topology structure and the forwarding protocol. CFTO offers two main contributions. First, it provides incentives for acting honestly and diminishing malicious and dishonest nodes. To accomplish this, we use a reputation system, whereby each node is given a reputation score based on its actions. Second, it consists of an algorithm that evaluates the proposed blocks based on the zone structure of the network. Furthermore, we adapt the evaluation algorithm to fit the additional order constraints implied in Ethereum transaction ordering. We demonstrate the improved accuracy of CFTO in detecting fair blocks, in terms of increasing the probability of approving fair blocks and decreasing the probability of approving unfair blocks, by implementing experiments and comparing them with Helix (Yakira et al., 2021), a previously proposed consensus algorithm for fair block selection. As part of our experiments, we also compare certain features with those of previous studies.

中文翻译：

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CFTO：区块链交易排序中的通信感知公平性


基于区块链领导者的协议选举领导者来提议下一个交易块。提议的区块需要通过验证例程才能添加到区块链中。提议者可能会根据其费用或账户对某些交易进行优先级排序，这使得攻击者能够通过区块构建获得利润，同时对其他用户造成负面影响。公平的区块选择是在提议者知道的交易中随机选择待处理的交易。我们提出了 CFTO，该协议旨在鼓励基于领导者的区块链网络中公平的区块选择，同时考虑到真实的网络条件，例如网络的拓扑结构和转发协议。 CFTO 提供了两个主要贡献。首先，它提供了诚实行事并减少恶意和不诚实节点的激励。为了实现这一目标，我们使用信誉系统，每个节点根据其操作获得信誉评分。其次，它由一种算法组成，该算法根据网络的区域结构评估提议的块。此外，我们调整评估算法以适应以太坊交易排序中隐含的附加订单约束。我们通过实验并将其与 Helix 进行比较（Yakira 等人，2021 年），证明了 CFTO 在检测公平区块方面的准确性有所提高，即增加了批准公平区块的概率并降低了批准不公平区块的概率。提出了公平区块选择的共识算法。作为我们实验的一部分，我们还将某些特征与以前的研究进行了比较。