基于门限和环签名的抗自适应攻击拜占庭容错共识算法

A Robust Byzantine Fault-tolerant Consensus Algorithm Against Adaptive Attack Based on Ring Signature and Threshold Signature

共识算法作为区块链底层关键技术,可解决决策权分散的分布式系统中的一致性难题.良好的共识算法可提升系统健壮性,但大多数方案在网络故障或主动攻击下存在鲁棒性不可控、活性表现差、可扩展性不足等问题.针对上述问题,提出一种抗自适应攻击的健壮拜占庭容错共识算法(Robust Byzantine fault tolerance,RBFT).该算法利用环签名的无条件强匿名性构造排序选主算法,隐匿选举每一轮共识中的提案者,进而达到模糊敌手攻击对象、有效抵抗自适应攻击的目的.同时,通过在多轮投票中合成代表法定人数投票意愿的门限签名,将网络划分为众多最小连通性网络,以保证在最小连通性网络环境中实现低延迟、高鲁棒性的拜占庭容错共识算法.分析表明,系统在提升可扩展性、减少视图更换、降低签名验证开销的同时,能够有效保证系统活性.

As the fundamental key technology of blockchain,consensus algorithms can resolve the consistency problem in the distributed system with decentralized decision-making authority.Fine-designed consensus algorithms can improve the robustness of system,but most of the schemes have the drawbacks of uncontrollable robustness,poor activity performance and insufficient scalability in the case of network failure or active attack scenarios.Given problems above,this paper proposes a robust Byzantine fault tolerance(RBFT)algorithm resistant to adaptive attacks.Using the ring signature with unconditional strong anonymity,the RBFT algorithm constructs an ordering and master-selecting algorithm to anonymously elect the proposer of every round of consensus,by which the attack object can be obscured from the adaptive attack.Meanwhile,by generating the threshold signature of the designated voters,the network is divided into a number of minimum connected networks to ensure consensus with low latency and high robustness.The analysis shows that by using the proposed RBFT algorithm,the system scalability can be improved,view change frequency and signature verification overhead can be reduced,at the same time the system activity can be effectively guaranteed.