A survey on the throughput of Blockchain Systems

PhD Qualifying Examination


Title: "A survey on the throughput of Blockchain Systems"

by

Mr. Yuechen TAO


Abstract:

By enabling multiple applications with security guarantee in a decentralized 
manner, rather than relying on the centralized services, blockchain systems 
have attracted great attention from both academia and industry in recent years. 
Different from the traditional online centralized services, to ensure the 
security and consistency, all users in Blockchain systems cooperate working 
together to validate each transaction. Hence, invalid transac- tions can always 
be located and eliminated.

However, as discussed in the recent literature and data analysis derived from 
real-world implementations, the throughput of the current Blockchain systems 
suffers significantly. The reason behind such low throughput is the fact that 
only one transaction can be confirmed at one time, no matter how many users are 
validating incoming transactions. In other words, the current Blockchain system 
is a serialized system. Bounded by the limited transaction processing ability, 
users typically experience a long delay before they can obtain the transaction 
confirmation requested. Since the confirmation time dictates user experience, 
this has to be carefully addressed.

This survey systematically reviews the state-of-the art throughput improvement 
tech- niques. Proposals based on revising the consensus achievement process 
aims to decrease the confirmation time needed per transaction. Sharding 
technique tries to parallelize the validation process to accelerate the overall 
confirmation process. There are also methods using channels for off-chain 
transactions to decrease the number of unconfirmed transac- tions. We further 
examine the tradeoff between the performance and security in different 
solutions and highlight our solutions.


Date:			Monday, 6 May 2019

Time:                  	3:00pm - 4:30pm

Venue:                  CYTG003
                         Lifts 35/36

Committee Members:	Prof. Bo Li (Supervisor)
 			Prof. Lei Chen (Chairperson)
 			Dr. Yangqiu Song
 			Dr. Wei Wang


**** ALL are Welcome ****