Delegated Proof of Stake With Downgrade: A Secure and Efficient Blockchain Consensus Algorithm With Downgrade Mechanism

Fan Yang,Qingqing Wu,Neal N Xiong,Wei Zhou,Rui Long,Meiqi Zhou

doi:10.1109/access.2019.2935149

Fan Yang, Qingqing Wu + Show 4 more

Open Access

https://doi.org/10.1109/access.2019.2935149

Copy DOI

Journal: IEEE Access	Publication Date: Jan 1, 2019
Citations: 208	License type: CC BY 4.0

Affiliation: Zhongnan University of Economics and Law

Abstract

Blockchain technology has a wide range of applications in the fields of finance, credit reporting and intellectual property, etc. As the core of blockchain, consensus algorithm affects the security and performance of blockchain system directly. In the past 10 years, there have been about 30 consensus algorithms such as Proof of Work (PoW), Proof of Stake (PoS), Delegated Proof of Stake (DPoS), Ripple Protocol Consensus Algorithm (RPCA) and AlgoRand. But their security, stability and operating efficiency still lag far behind our actual needs. This paper introduces the computing power competition of PoW into DPoS to design an improved consensus algorithm named Delegated Proof of Stake with Downgrade (DDPoS). Through the further modification, the impact of both computing resources and stakes on generating blocks is reduced to achieve higher efficiency, fairness, and decentralization in consensus process. Then a downgrade mechanism is proposed to quickly replace the malicious nodes to improve the security. The simulation experiments in blockchain system show that the proposed consensus algorithm is significantly more efficient than PoW and PoS, but slightly lower than DPoS. However, its degree of centralization remains far below that of DPoS. And through the downgrade mechanism, the proposed consensus algorithm can detect and downgrade the malicious nodes timely to ensure the security and good operation of system.

Highlights

On 1 Nov. 2008, Satoshi Nakamoto has published a paper [1] on www.metzdowd.com, which marked the birth of Bitcoin and showed people the blockchain
With the continuous development of blockchain technology, the consensus algorithm is constantly adapting to the emerging requirements from the earliest Proof of Work (PoW) [1] to the later Proof of Stake (PoS) [13], Delegated Proof of Stake (DPoS) [14], Practical Byzantine Fault Tolerance (PBFT) [15] and some other improved consensus algorithms such as Proof of Burn (PoB) [16], Proof of Activity (PoA) [17], Proof of Luck (PoL) [18], and Stellar Consensus Protocol) (SCP)[19]
The innovations of this paper are as follows: The first is the idea of combining the advantages of PoW and DPoS to improve the original DPoS algorithm

Summary

INTRODUCTION

On 1 Nov. 2008, Satoshi Nakamoto has published a paper [1] on www.metzdowd.com, which marked the birth of Bitcoin and showed people the blockchain. From the blockchain consensus environment of DDPoS algorithm shown, we can see that the trading nodes are responsible for the creation, broadcasting and storage of transaction’s information, the witness nodes take turns to record transactions into a block and broadcast the block to the other consensus nodes for validating. DDPoS algorithm will complete the transition of the state tag of consensus nodes N C i in nodes set N W and N A, and deprive the right of generating block of the faulty witness node N W ERROR through downgrading it into the candidate nodes set. Step 7: After the downgrade operation between the witness nodes set N W and the candidate nodes set N A is completed, and the N W and N A are regenerated, the blockchain system sets the state to NORMAL, the witness node N W i starts to generate blocks, and the consensus node N C i performs verification on them.

1: N W γ Broadcast BLOCKERROR

Findings

CONCLUSION AND FUTURE WORK