Blockchain testing, big data analytics, stopping the tendency
to centralization, smart security analysis and artificial
intelligence [3]. In November 2018, challenges and security
with Blockchain were surveyed by Tunisia researchers [150].
In December 2018, Chen et al. surveyed only on Blockchain
applications on different domains [47].
In August 2019, Monrat et al. conducted survey on
Blockchain architecture including transaction process, block
structure and characteristics of Blockchain, category of
Blockchain, consensus procedures, Blockchain applications,
trade-offs and future scope of Blockchain technology [49]. In
November 2019, Dave et al surveyed the implementations of
Blockchain technology in agricultural sector, education
sector, supply chain management, healthcare industry, etc
[48]. In March 2020, Aguiar et al. surveyed and used
Blockchain technology to boost healthcare security and
reliability and enhance patient privacy [30]. One survey work
received in December 2019 and published in April 2020
presented the Blockchain technology, applications and issues
including scalability, nothing-at-stake, etc [31]. In 2020, Saad
et al. presented the systematical overview about the
Blockchain attack surface [151]. In January 2021, Berdik et
al. presented their survey paper on Blockchain to ensure the
information integrity and security [32].
There are some survey papers on Blockchain security. In
2019, Dasgupta et al. surveyed the potential vulnerabilities of
Blockchain and showed Blockchain development trends
[152]. In 2020, Leng et al. examined Blockchain security
from the process level, the data level and the infrastructure
level to identify the research gap and suggest future directions
of research in Blockchain security [153].
Table IX summarizes the related survey work and our
work in this paper. It is also clear to show our contributions in
this paper. First, we provide as many quantitative comparisons
on consensus algorithms as possible while others only
provided partial comparisons. Second, the security on
Blockchain itself is a focus in this paper, which the majority
of previous surveys only partially presented or did not present,
and some survey papers on Blockchain security surveyed the
potential vulnerabilities, and examined security in process,
data and infrastructure levels respectively. In our paper, we
assess the Blockchain security from risk analysis to derive
comprehensive Blockchain security risk categories, analyze
the real attacks and bugs against Blockchain and root causes,
and present the recently developed security measures on
Blockchain. Last but not list, Table IX shows that other survey
papers cover 2 to 7 areas respectively, while our work consists
more comprehensive survey on 8 areas of Blockchain.
T
ABLE
IX.
S
UMMARIES OF
V
ARIOUS
S
URVEY
W
ORKS
