Design and Analysis of an Effective Securing Consensus Scheme for Decentralized Blockchain System

Abstract

Blockchain, as a decentralized network system, has been attracting increasing attention in recent years. In a blockchain system, there must be a consensus mechanism to ensure the distributed consensus among all parties. Such consensus mechanism may also be applied to guarantee fairness, correctness, and sustainability of such decentralized systems. In this paper, we propose a novel consensus mechanism, named Proof-of-Credibility (PoC), which is an improved version of Proof-of-Work (PoW). Compared with existing consensus mechanisms, PoC provides strong resistance to resource centralization and other malicious attacks. First, we present the Serial Mining Puzzle (SMP) to resist collusive mining. SMP guarantees that participants only get negligible advantage by parallel solving. Second, PoC considers the influence of participant credibility, which is reflected by the mining behaviour of a participant. Thus, credible participants get higher probability of winning the mining competition than incredible ones. Finally, the performance of PoC is analyzed in terms of common prefix, chain quality and power cost. Our analysis indicates that PoC is security and incentive compatible with suitable security parameter settings.