Abstract:

[Objective] Blockchain consensus mechanism is the key technology to solve the account books consistency problem in the process of point-to-point communication in blockchain.[Coverage] More than 40 related literatures from CNKI, ACM, CCS, etc. on blockchain, smart contract technology and various consensus mechanisms are referred. [Methods] This paper divides consensus mechanisms into two categories: proof consensus mechanism and Byzantine consensus mechanism. This paper first introduces five consensus algorithms: POW, POS, DPOS, POA and PBFT consensus algorithm, and then analyzes and compares their advantages and disadvantages. Aiming at reducing the defects of various consensus algorithms, two improved consensus algorithms are introduced, including honey badger algorithm and little flying elephant negotiation algorithm. [Results] Each consensus mechanism has its own advantages and disadvantages. Different consensus mechanisms should be applied to different scenarios to play their roles. [Limitations] Due to the limited space, this paper is not able to give a detailed introduction to a specific consensus mechanism technology. [Conclusions] Each different consensus mechanism has its own shortcomings. Thus, we can improve consensus mechanisms by reducing their shortcomings.

Key words: blockchain, consensus mechanism, smart contract