Conference PaperPDF Available

Blockchain in WSNs, VANets, IoTs and Healthcare: A Survey



Recently, blockchain technology has become one of the most groundbreaking technology. Blockchain was introduced to support digital transactions and, provide access to the distributed ledger in a secure and trusted way. Blockchain with smart contracts has the ability to provide secure transaction among users without the need of trusted third party or intermediary. In this paper, we presented a comprehensive survey on blockchain applications for Wireless Sensor Networks (WSNs), Vehicular Adhoc Networks (VANets), Internet of Things (IoTs) and healthcare. We review the problems addressed, their proposed solutions and, experimental evaluation security analysis. We also spot and review future challenges or open research issues of utilizing blockchain for WSNs, VANETs, IoTs, and healthcare.
Blockchain in WSNs, VANets, IoTs and
Healthcare: A Survey
Fatima Tariq, Nadeem Javaid, Maria Anwar, Abdul Rehman Janjua, Muhammad
Haseeb Khan and Asad Ullah Khan
Abstract Recently, blockchain technology has become one of the most ground-
breaking technology. Blockchain was introduced to support digital transactions and,
provide access to the distributed ledger in a secure and trusted way. Blockchain with
smart contracts has the ability to provide secure transaction among users without the
need of trusted third party or intermediary. In this paper, we presented a compre-
hensive survey on blockchain applications for Wireless Sensor Networks (WSNs),
Vehicular Adhoc Networks (VANets), Internet of Things (IoTs) and healthcare. We
review the problems addressed, their proposed solutions and, experimental evalua-
tion security analysis. We also spot and review future challenges or open research
issues of utilizing blockchain for WSNs, VANETs, IoTs, and healthcare.
1 Introduction
Blockchain is considered as one of the most hyped and disruptive innovations nowa-
days and can be used to solve the problem of double spending attack and to maintain
the order of transactions. It continues to develop in such a way that will modern-
ize the way we interact, trace, and track payments among participants. Blockchain
was first introduced for digital transactions with bitcoins, and now it is adopted
by various cryptocurrencies [1]. The transactions are grouped into size-constrained
structure labeled as blocks, with the similar timestamp. Miners are responsible for
achieving consensus and link the blocks with each other in chronological order, and
every block encompasses the hash of the preceding block to make the blockchain.
Depending on the type of blockchain, different consensus algorithms are used. PoW
is very well-known algorithm and solves complicated computational problems like
finding hashes to guarantee authenticity and verifiability. As an alternative of divid-
Fatima Tariq, Nadeem Javaid (Corresponding Author), Maria Anwar, Abdul Rehman Janjua,
Muhammad Haseeb Khan and Asad Ullah Khan
COMSATS University Islamabad, email:
2 Fatima et al.
ing blocks evenly to the mining power of miners, Proof of Stake (PoS) is used to
divide blocks evenly to the current wealth of miners. PoS allows just selection of
blocks and avoids the well-off member to lead the network of blockchain. Several
applications of blockchain are shifting towards PoS because it provides enhanced
scalability and prominent decrease in computation power. Other consensus algo-
rithms include Proof of Concept (PoC), Byzantine Fault Tolerance (BFT) and its
modifications [2].
The blockchain technology provides transparency, trustless, but secure transac-
tions in the decentralized network, which helps in attaining robust and auditable
records of all transactions. Hence, blockchain is applied to different scenarios for
Wireless Sensor Networks (WSNs), Vehicular Adhoc Networks (VANets), Inter-
net of Things (IoTs) [3, 4, 5], smart grids [6] and healthcare. In these scenarios,
blockchain is used with smart contracts, which are lines of code of protocol and exe-
cute the terms and conditions of the contract between two parties [2]. Smart contract
helps in translation of contractual clauses into embeddable code, which minimizes
the need for trusted third party and transaction are truly between two parties. In
general, smart contract is an agreement between two parties who do not trust each
other, so contractual clauses are automatically imposed.
Blockchain in WSNs is a big challenge, as sensor nodes have limited volume
of batteries which results in limited number of operations, so the whole network is
limited. The dependence of energy consumption depends on the amount of trans-
mitted, received and processed information, data acquisition from sensor nodes and
some other factors. The use of Proof of Work (PoW) is also a big task, as PoW is a
resource and energy intensive task. Same is the case with IoT devices [7]. Managing
vast number of IoT devices is a technical challenge. So, blockchain was adopted to
develop a distribuited environment in WSNs and IoTs. As mechanical vehicles are
evolving into fully automated vehicles. The current security mechanisms provided
by researchers are not up to date. In vehicular networks blockchain can be used to
provide authentication, trust and security between vehicle to vehicle and vehicle to
infrastructure communication [8].
In healthcare industry, patient’s data is the most critical and sensitive information.
Patients’ medical record is mostly scattered around different hospitals and systems
owned by healthcare industry. Digitalization has the ability to store the medical
record of patient digitally, which is known as Electronic Medical Record (EMR)
[9]. In this scenario, blockchain can be used to enable the distributed system of
EMR and to enable its security and privacy while data sharing [10]. Blockchain
comes with challenging and technical tasks in these scenarios. There are several
good surveys discusssing basic blockchain concepts, opportunities and applications
[11, 12]. Some papers focused specific aspects such as security, privacy, scalability,
consensus algorithms and some future challenges [13, 14].
To date, the literature lacks comprehensive study of problems addressed, their
solutions, how authors have validated their proposed solutions and future research
directions. In this work, we will discuss the problems addressed related to these do-
mains in current state-of-the-art. The proposed solutions to the concerned problems
is also summarized and is given in Table 1.
Blockchain in WSNs, VANets, IoTs and Healthcare: A Survey 3
The remainder of this paper is organized as follows: In Section 2, problems ad-
dressed of the current state-of-the art is presented. The proposed solutions to solve
these problems are summarized in Section 3. The validation of the proposed so-
lutions is presented in Section 4 while in Section 5 future research directions are
Platform Problem Addressed Contributions Techniques Future Challenges
Secure and private communication between
vehicles in ITS. [8]
Proposed security mechanism based on IVTP
to provide P2Pcommunication between vehicles
in ITS.
PoW Wastage of processing powerand
Security and privacy between vehicular networks
in smart city. [15]
Proposed a Block-VN architecture based
on blockchain in smart city for vehicular networks.
PoW,Public-private key
Does not provide security
or experimental analysis.
Data Storage Storage bloating problem in blockchain. [16] Authors proposed binary field random shift
encoding method with low complexity.
Deterministic NC-DS &
Rateless NC-DS
The proposed solution is not
resistant to pollution attack.
Traceability data is difficult to maintain on
Blockchain and IPFS based system for
data provenance and query mechanism for tracking.
The tradeoff between the capacity
of packet and storage efficiency
needs to be further studied.
Less involvement of users and fakedata
is uploaded to protect the personal information.
Blockchain based incentive mechanism. SHA-256, Merkle tree
Experimental evaluation is based
on a small number of samples. So,
the results can be one-sided.
Resource constrained devices in WSNs. [7] Designed a Rolling blockchain without PoW Monte Carlo tests Security analysis against malicious
nodes is not provided.
Data Sharing
Data barriers between MNOs. [19] Mutual trust based data sharing framework with fine
grained access control
PBFT Computation overhead
Research data rights management. [20] Provides a method for managing rights of digital
reuse of data using blockchain and smart contracts.
To maintain the data requester in
line with defined terms, incentive
mechanism can be integrated.
Centralized energy trading system. [21] Chord based distributed system for decentralized
energy trading.
Chord Algorithm
The strategy to prevent numerous
attacks, especially for overlay net
work, is needed.
Centralized access management framework for
IoT have some limitations. [22]
Distributed IoT system based on blockchain PoC
The solution proposed does not
achieve better performance in the
case of a single management hub.
Latency overhead, bandwidth consumption,
security and privacy concerns in IoT.[23]
Proposed hybrid smart city network with the
technology of blockchain and SDN architecture.
Argon2 based PoW
The proposed system model needs
efficient utilization of edge nodes
and related work can be carried out
by facilitating cache memory at the
edge nodes.
Privacy and security issues in IoT data management.
Distributed IoT system based on blockchain. BFT
Privacy protection of IoT data is
not managed. Huge network traffic
overhead because of BFT.
Wastage of storage in existinghealthcare data sharing
scheme. [25]
Proposed efficient data sharing scheme known
as MedChain and provide required security
requirements in healthcare data sharing.
Inefficient upload of data, Over
head of operation and latency in
data access for requester.
Lack in current EHR systems for data sharing and
management. [26]
Proposed a blockchain based MedBlock framework
for data sharing and management.
PBFT, Asymmetric
High storage overhead, Data stor-
age problem on databases.
Private and secure storage of medical data. [27] Proposed a secure storage scheme for medical data
based on blockchain.
PoW Interoperability is not tested, High
energy cost.
Table 1: Summarized Literature Review
2 Problems Addressed
In this section, we discuss the problems addressed by the authors in the existing
4 Fatima et al.
2.1 Blockchain in Vehicular Networks
In this modern era, mechanical vehicles are moving towards automation. Intelli-
gent Transportation System (ITS) uses ad hoc networks for communication between
vehicles, which is not secure. At present, security protocols used for communica-
tion between vehicles are not suitable for ITS applications. So, authors in [8] pro-
posed a standard security mechanism for ITS. For setting up a trust relationship
between clients in vehicular networks, security and privacy are the main concerns.
The primary security issues of vehicular networks include: examining verification
of clients, confidentiality of the message and guaranteeing safe area or location (ve-
hicular network mainly depends on area data). The security and privacy issues of
vehicular network are further investigated by authors in [15].
2.1.1 Blockchain-based Data Storage
Each node stores all transactions generated by all the previous blocks in blockchain.
Consequently, the volume of data increases linearly with time. The rapid increase
in the volume of data may cause the problems of lack of storage room and unsus-
tainable expansion of system size. The above mentioned problems can be named
as a storage bloating problem. Few works have been done to manage this problem,
however certain amount of information was lost in this work. In [16], authors re-
solved the storage bloating problem without losing a certain amount of information.
Logistics management systems are emerging day by day. Even though the systems
can automatically trace the complete process, the provenance data can be tampered
in the traditional systems. As the blockchain was designed for digital transactions
so it has limited storage and it is is difficult to maintain the traceability data on the
blockchain [17].
2.1.2 Blockchain in WSNs
In [18], Crowd Sensing Networks (CSNs) collect sensing data by using sensors car-
ried by mobile phones or any IoT devices to save cost. The main issue of CSN is
the leakage of privacy. The privacy leakage problem results in less involvement of
users and false data is uploaded to safeguard their personal information. WSN nodes
and mobile devices have a limited number of resources. The usage of a blockchain
network in smart sensor networks is impossible because sensors are resource con-
strained devices and do not have enough computation power to perform PoW con-
sensus algorithm. The blockchain network requires a permanent connection between
nodes, which is not energy efficient. So, the blockchain without PoW is required,
which allows partial connectivity at the same time as to resist errors and adversary
activities [7].
Blockchain in WSNs, VANets, IoTs and Healthcare: A Survey 5
2.1.3 Blockchain-based Data Sharing
Mobile communication and networking lead to the creation of a very complex sys-
tem. Artificial Intelligence (AI) based network frameworks are introduced to operate
the network automatically. However, mobile network operators are currently facing
the problem of data barriers. So, a framework for data sharing based on mutual trust
was established to break barriers of data between different mobile network opera-
tors [19]. The main barriers of data sharing in research are due to the fear of misuse
of data and its wrong interpretation. Authors in [20] proposed a secure network to
share research data so that the owner can oversee how the data is being accessed
and reused. The demand and supply of energy is increasing day by day. For this pur-
pose, energy suppliers and consumers are there to buy and sell energy, this is known
as energy trading. The present centralized state of energy trading system is facing
security and privacy problems. The decentralized energy trading based on Bitcoin
protocol was proposed, which lacks the description of attacker performance. For
the management of energy, green blockchain concept was introduced, which lack
the details of security issues in the proposed system. So, an efficient energy trading
system was proposed in [21] for the loss of transmission in the smart grid.
2.1.4 Blockchain in IoT
With the growth of IoT, the management of an enormous number of IoT devices is
a technical challenge. Existing management frameworks for IoT are based on cen-
tralized models and their applications have some limitations in scenarios with large
number of IoT devices [22]. With the rise of IoT devices, smart cities are being de-
veloped. As the volume of data increases, it leads to latency overhead, bandwidth
consumption and issues in security and privacy concerns. Today’s smart city net-
work requires to bring computing and storage resources closer to the endpoint [23].
Data management of a large number of IoT devices is a critical issue. Existing so-
lutions used centralized systems for controlling IoT devices, which bring issues of
privacy and security in IoT data management. Blockchain has been used in the field
of IoT because it provides decentralization, immutability and traceability. However,
due to the issue of scalability and high cost of resources, it is not trivial to employ
blockchain in IoT scenario [24].
2.1.5 Blockchain in Healthcare
According to authors in paper [26], existing blockchain-based healthcare solutions
are not efficient enough to share data from IoT devices. Data from IoT devices are
stored in chunks and to access the data stream the entire chunks of data need to
be accessed. The existing scheme downloads digest of each chunk and checks the
integrity of all of them, which is not an efficient process. Since the information
stored on the blockchain is immutable, so the transitory information such as crypto-
6 Fatima et al.
graphic keys and location of actual data cannot be removed after data sharing. This
transitory information results in wastage of storage. With the application of IoT in
healthcare, a large amount of data is shared, and storage overhead is an unresolved
problem. Consequently, efficient sharing of healthcare data becomes a nascent prob-
lem. To achieve the excellence of healthcare providers and to make the healthcare
system smarter, sharing of data and medical records is the key step. Data sharing in
healthcare is done between individuals such as sharing of patient’s data with stake-
holders. In today’s healthcare systems, patient scarcely has access to the healthcare
data. Blockchain plays a vital role in increasing the collaboration between patient
and healthcare industry and enables a secure and appropriate mechanism for shar-
ing Electronic Health Record (EHR) [25]. EHR is considered as valuable asset for
patients and although, private and secure storage of medical data is a critical issue.
In [27], authors addressed the issue of secure storage and sharing of medical data.
3 Contributions
The following section describes the contributions and the solutions proposed by the
3.1 Blockchain in Vehicular Networks
In [8], authors proposed a security mechanism based on blockchain for secure and
intelligent vehicles communication. Authors introduced branching and unbranch-
ing of Local Dynamic Blockchain (LDB) for achieving efficiency. Intelligent Vehi-
cle Trust Point (IVTP) is introduced to provide Peer-to-Peer (P2P) communication
between vehicles without disturbing other intelligent vehicles and provides trust
between vehicles without exposing their private information. Two blockchains are
proposed in this mechanism to overcome the challenge of data storage and man-
agement. Authors proposed a Block-VN model based on blockchain in a smart city
for vehicular networks [15]. The proposed model allows vehicles to share their re-
sources and create a network to generate value added services. Service scenarios
and principles of requirement are also discussed in this paper.
3.2 Blockchain-based Data Storage
Authors in [16] tackled storage bloating problem, using Network Coding based Dis-
tributed Storage (NC-DS) without losing any information. Deterministic NC-DS
and rateless NC-DS are the two implementations of NC-DS. Rateless NC-DS has
large encoding and decoding complexity, which is not suitable for devices with lim-
Blockchain in WSNs, VANets, IoTs and Healthcare: A Survey 7
ited computing and energy resources. Therefore, authors proposed a low complexity
design method known as binary field random shift encoding. The proposed solution
provides a major improvement in saving storage space. In [17], authors proposed a
system with the combination of Inter-Planetary File System (IPFS) and blockchain
for data provenance, and query mechanism for tracking agricultural products. Large
amount of provenance data from IoT devices is stored on IPFS and hash addresses
of corresponding data is stored on blockchain. Each transaction on blockchain stores
the hash of previous transaction which ensures traceability and usability of data.
3.3 Blockchain in WSNs
To solve the problem of privacy protection, authors proposed a blockchain based
incentive mechanism. The proposed network in [18] is divided into three parts: CSN,
confusion mechanisms and blockchain. The server receives sensing data from the
blockchain and publishes the information of task. Confusion mechanism process
the data of nodes present in the CSN to achieve the effect of unclarity and privacy
leakage is prevented. In addition, coins are rewarded after successfully storing user
data on the blockchain. More the users participate, the more coins are rewarded
to them. So, the proposed solution increases the involvement of user and provides
privacy protection. Authors proposed a blockchain with several parts and each part
contains a constant number of generated blocks. The amount of blocks depends
on the resources of devices in the IoT network. The concept of rolling blockchain
proposed in [7] is used to build a WSN with smart cars as nodes of the network. A
mathematical model is created for the formation of the blocks and its structure in
the chain.
3.4 Blockchain-based Data Sharing
In [19], authors proposed a fine-grained access control data sharing framework and
data security is improved by smart contracts and permissioned blockchain. Two
types of blockchain: DataChain and BehaviorChain are combined to provide a trust-
less environment for data sharing and supervision of access control. Authors in [20]
proposed a method for managing rights of digital reuse of data using blockchain and
smart contracts. The new mechanism allows the user to define reuse terms and pro-
vides a way to track and validate the execution of terms. In [21], authors proposed
an overlay network based on a chord-based distributed system in a decentralized
energy trading system, which finds the location of nodes among neighbours. The
system is based on blockchain and possible security issues are analyzed.
8 Fatima et al.
3.5 Blockchain in IoTs
To overcome the aforementioned problems in [22], authors proposed a distributed
IoT system based on blockchain. Proof of Concept (PoC) architecture that uses
blockchain to implement access management system for IoT is presented. The ac-
cess control permissions for different IoT devices are stored in blockchain. The pro-
posed solution is suitable for horizontal scalability, where WSNs are connected to
multiple management hubs. Smart city network with the technology of blockchain
and Software Defined Networking (SDN) architecture was introduced. Authors pro-
posed Argon2 based PoW scheme for security and privacy and ensured the integrity
of data. The network proposed in [23] consists of core and edge network, which
helps in achieving properties of a centralized and decentralized network. For ef-
ficient and secure data management in IoT, authors proposed a cross-chain based
framework in [24]. They integrated tangle into the blockchain network and built a
cross-chain based framework for IoT data management. To overcome the challenge
of scalability of IoT blockchain, authors used tangle, which uses a Directed Acyclic
Graph (DAG) data structures, and divide the data into several small sub-Tangles
just like side chains. The sidechains are then connected to form a decentralized net-
work. Decentralized consortium blockchain connects the sub-Tangle with itself and
securely logs incoming requests for data access control and execute access control
mechanism on these requests.
3.6 Blockchain in Healthcare
Authors proposed a new data-sharing solution known as MedChain [25], which is
based on two decentralized networks. P2P storage, which stores mutable data such
as a description of data and session. Second is the blockchain network which stores
immutable data, for instance, data digest. By separating mutable data from the im-
mutable, description of data is effortlessly updated and does not results in a further
overhead to the blockchain network. For the verification of the data stream, a new
digest chain is introduced, and for the reduction in storage overhead, a session is
introduced, which helps to remove the transitory or mutable information. In [26],
authors proposed a Medblock framework for data management and data sharing
in EHR based on blockchain and improve the sharing of medical information. By
this framework, patients can access the EHR of different hospitals by getting rid of
the previous healthcare data stored in segments on innumerable databases. Authors
proposed a blockchain based secure storage scheme for medical data sharing. In
the proposed scheme [27], authors explained three types of permissions of transac-
tion bodies. Authors also designed structure of block and key roles of blockchain
in healhcare scenario. The introduced blockchain can provide patient EHR without
compromising security.
Blockchain in WSNs, VANets, IoTs and Healthcare: A Survey 9
4 Validation
In this section, the discussions of the experimental results of existing works in liter-
ature are given.
4.1 Blockchain in Vehicular Networks
In [8], the average time taken for the verification of State Change (SC) increases
as the load on the system increases. The tests are performed using the branching of
LDB, to compare the performance of branched LDB with unbranched. For the load
of 2400 SCs/min, the average time taken for SC validation has decreased sharply for
LDB with four branches. The branching of LDB results in speeding up the process
of consensus algorithm. When the load is further increased up to 3200 SCs/min, the
average time taken for SC validation has decreased and the results of LDB with four
branches are much better than unbranched blockchain. In [15], the authors do not
perform any security or experimental analysis.
4.2 Blockchain-based Data Storage
In [16], authors analyzed their proposed solution based on storage, bandwidth, con-
sensus speed and scalability. Deterministic NC-DS uses half of the storage room
as compared to the traditional blockchain system and rateless NC-DS uses slightly
large storage room as compared to the deterministic NC-DS. In the proposed solu-
tion, the volume of data to be distributed is half of the original. There is no effect on
the consensus speed and the framework is scalable. The scheme in [17] is validated
on the basis of data uploaded per minute versus data processed per minute. As the
amount of data increase, the processed data continue to increase.
4.3 Blockchain in WSNs
In [18], experiments are performed on android studio and eclipse. Data is collected
from hundred people and the experiments performed show that men are more con-
cerned about privacy than women. The proposed solution has less time complexity
as compared to the existing one. The results from the simulations show that with the
increase in a number of lost connections and nodes, the network remains unaffected
and blockchain can be formed. Monte Carlo tests are performed to numerically find
the alternative path, when the position of links with different node densities is re-
moved randomly. In [7], the results show that as the level of attack increases the
10 Fatima et al.
network is unable to provide alternative paths until it seizes up. In the scenario with
low sensor density, the network seizes up at low intensity of attacks.
4.4 Blockchain based Data Sharing
Proposed system in [19] provides privacy, security and scalability. Privacy is pro-
vided by encryption of data and then the data is stored on cloud database. Only
hashes are saved on blockchain for integrity verification. The PBFT consensus al-
gorithm is used which does not create a hurdle to scalability. In [20], authors provide
a brief analysis of transaction costs of execution of functions in smart contracts and
the actual execution cost. The total cost for executing smart contracts is less than
two US dollars which is negligible as compared to other open access publishing
expenses that can easily go over one thousand US dollar. In [21], authors analysed
security issues such as selfish mining and double spending attack. The results show
that approximately thirty percent of blocks are generated between ten minutes.
4.5 Blockchain in IoT
Authors in [22] performed evaluation of existing management systems against pro-
posed solution. The evaluation shows that the proposed solution is more scalable
than conventional scenarios when the load of IoT devices is distributed among nodes
of blockchain network. The experiments performed show that the difficulty in the
proposed scheme is regulated based on the hash rate. The proposed scheme in [23]
performs more efficiently as the size of the block depends on the number of trans-
actions per second and it is more robust as the system proposed has desired average
time per block. The latency is also reduced as compared to the public Ethereum
blockchain. The throughput and latency for different transactions in a network are
tested under different configuration environments in [24]. As the memory and num-
ber of CPU cores increases, the throughput of the network becomes closer to the
default send rate value, and latency of processing of transactions is also decreased.
With memory and CPU, network traffic of the system is also tested. The traffic over-
head is evaluated by monitoring incoming and outgoing traffic of the peer container
of Fabric network.
4.6 Blockchain in Healthcare
The proposed scheme in [26] is validated based on a delay in data retrieval. The
breadcrumb mechanism proposed in this work helps the user to directly retrieve the
useful information instead of traversing the whole block until the useful or required
Blockchain in WSNs, VANets, IoTs and Healthcare: A Survey 11
information is found. As the number of users increases, the efficiency of data re-
trieval is significantly improved. The efficiency of the system is also improved by
uploading data asynchronously to avoid system congestion and high load on the sys-
tem. Authors validated the proposed scheme in [25] on the basis of communication
overhead, storage overhead and scalability. In this work, the digest of the data stream
is encoded into a digest chain. This scheme can avoid communication overhead as
to perform data integrity check, only the last chunk of data needs to be extracted
instead of downloading the whole stream. The storage overhead is also removed,
as only the fingerprints are stored on the blockchain and other mutable information
is stored in the directories. The scalability is validated by increasing the number of
directory nodes. As the number of directory node is increased, the response of the
system also increases sub-linearly. The proposed system in [27] is analyzed with tra-
ditional systems, which proves that it can provide privacy protection, secure storage
and is tamper proofed.
5 Limitations/Future Directions
In this section, we outline the limitations or future research directions of the existing
5.1 Blockchain in Vehicular Networks
In [8], branching comes with shortcomings of a high amount of duplicate SCs em-
bedded in blocks. As the load on the network increases, the number of duplicate
SCs per block is rapidly increased. The duplicate SCs lodged in blocks result in the
wastage of processing power and storage. The proposed model in [15] is not ana-
lyzed on the basis of security and experiments. The model needs further investiga-
tion to combine public storage of blockchain with distributed file system to manage
security, scalability and transparency.
5.2 Blockchain-based Data Storage
In the proposed scheme [16], each node stores distinct encoded packet so the error in
the single node can propagate to a large area. So, the basic assumption of blockchain
that adversary cannot compromise more than half of the resources of the system is
not followed in the proposed framework. The trade off between capacity of packet
and storage efficiency needs to be further studied in [17].
12 Fatima et al.
5.3 Blockchain in WSNs
In [18], the experimental evaluation is based on smaller number of samples and the
results can be one-sided and privacy protection can be enhanced with the improve-
ment of algorithm. The security analysis and protection against malicious nodes
are not provided in [7]. The proposed method can be extended to other topological
models with the integration of a Merkle tree.
5.4 Blockchain-based Data Sharing
In [19], two types of blockchain may result in computation overhead because mining
is performed on both DataChain and BehaviorChain. The proposed method in [20]
does not provide an incentive mechanism such as rewarding ethers or tokens when-
ever new data set is published, so that the participants stay in line with the defined
terms. The strategy to prevent numerous attacks, especially for overlay network, is
needed in [21].
5.5 Blockchain in IoTs
The solution proposed in [22] does not achieve better performance in the case of a
single management hub. The proposed system model in [23] needs efficient utiliza-
tion of edge nodes and related work can be carried out by facilitating cache memory
at the edge nodes. The proposed privacy access control scheme in [24] only ensures
privacy and protection of IoT data, privacy protection of user data is not considered.
The Byzantine Fault Tolerance (BFT) consensus algorithm is used, which has huge
network traffic overhead.
5.6 Blockchain in Healthcare
In [25, 26], authors have stored the data on the database, which results in latency
overhead. Authors also do not provide a fine-grained access control to the client for
data sharing. The solution proposed is unable to provide the record of data access
and how data is used by the requester. In [25], patient’s manual approval is needed
every time data is accessed, which results in the overhead of operation and latency
in data access for requester. The healthcare providers also manually upload data on
directory and blockchain network, which is inefficient. The interoperability of the
proposed system [27] is not tested, and it is not energy efficient because PoW is
used, which needs high computation power.
Blockchain in WSNs, VANets, IoTs and Healthcare: A Survey 13
In this paper, we described the recent state-of the-art related to the applicability of
blockchain for WSNs, VANets, IoTs and healthcare. Moreover, we presented the de-
tailed literature review which shows that adopting blockchain for above mentioned
scenarios is still in its initial stages. There exists many future challenges and di-
rections related to privacy, security, storage, consensus algorithm, scalability and
computational efficiency.
1. Salah, Khaled, et al. “Blockchain for AI: review and open research challenges.” IEEE Access
7 (2019): 10127-10149.
2. Casino, Fran, Thomas K. Dasaklis, and Constantinos Patsakis. “A systematic literature review
of blockchain-based applications: current status, classification and open issues.” Telematics
and Informatics (2018).
3. Mubariz Rehman, Nadeem Javaid, Muhammad Awais, Muhammad Imran, and Nidal Naseer.
“Cloud based secure service providing for IoTs using blockchain.” In IEEE Global Commu-
nications Conference (GLOBCOM 2019). 2019.
4. Tanzeela Sultana, Ahmad Almogren, Mariam Akbar, Mansour Zuair, Ibrar Ullah, and
Nadeem Javaid. “Data Sharing System Integrating Access Control Mechanism using
Blockchain-Based Smart Contracts for IoT Devices.” Applied Sciences 10, no. 2 (2020): 488.
5. Turki Ali Alghamdi, Ishtiaq Ali, Nadeem Javaid, and Muhammad Shafiq. “Secure Service
Provisioning Scheme for Lightweight IoT Devices with a Fair Payment System and an Incen-
tive Mechanism based on Blockchain.” IEEE Access (2019).
6. Omaji Samuel, Nadeem Javaid, Muhammad Awais, Zeeshan Ahmed, Muhammad Imran, and
Mohsen Guizani. “A blockchain model for fair data sharing in deregulated smart grids.” In
IEEE Global Communications Conference (GLOBCOM 2019). 2019.
7. Kushch, Sergii, and Francisco Prieto-Castrillo. “A Rolling Blockchain for a Dynamic WSNs
in a Smart City.” arXiv preprint arXiv:1806.11399 (2018).
8. Singh, Madhusudan, and Shiho Kim. “Branch based blockchain technology in intelligent
vehicle.” Computer Networks 145 (2018): 219-231.
9. Al-Jaroodi, Jameela, and Nader Mohamed. “Blockchain in Industries: A Survey.” IEEE Ac-
cess 7 (2019): 36500-36515.
10. Muqaddas Naz, Fahad A. Al-zahrani, Rabiya Khalid, Nadeem Javaid, Ali Mustafa Qamar,
Muhammad Khalil Afzal, and Muhammad Shafiq. “A Secure Data Sharing Platform Using
Blockchain and Interplanetary File System.” Sustainability 11, no. 24 (2019): 7054.
11. Lu, Yang. “Blockchain: A survey on functions, applications and open issues.” Journal of
Industrial Integration and Management 3.04 (2018): 1850015.
12. Lin, Iuon-Chang, and Tzu-Chun Liao. “A Survey of Blockchain Security Issues and Chal-
lenges.” IJ Network Security 19.5 (2017): 653-659.
13. Conti, Mauro, et al. “A survey on security and privacy issues of bitcoin.” IEEE Communica-
tions Surveys & Tutorials 20.4 (2018): 3416-3452.
14. Nguyen, Giang-Truong, and Kyungbaek Kim. “A Survey about Consensus Algorithms Used
in Blockchain.” Journal of Information processing systems 14.1 (2018).
15. Sharma, Pradip Kumar, Seo Yeon Moon, and Jong Hyuk Park. “Block-VN: A distributed
blockchain based vehicular network architecture in smart City.” JIPS 13.1 (2017): 184-195.
16. Dai, Mingjun, et al. “A low storage room requirement framework for distributed ledger in
blockchain.” IEEE Access 6 (2018): 22970-22975.
14 Fatima et al.
17. Hao, JinTao, Yan Sun, and Hong Luo. “A Safe and Efficient Storage Scheme Based on
BlockChain and IPFS for Agricultural Products Tracking.” Journal of Computers 29.6 (2018):
18. Jia, Bing, et al. “A Blockchain-Based Location Privacy Protection Incentive Mechanism in
Crowd Sensing Networks.” Sensors 18.11 (2018): 3894.
19. Zhang, Guozhen, et al. “Blockchain-based data sharing system for ai-powered network oper-
ations.” Journal of Communications and Information Networks 3.3 (2018): 1-8.
20. Panescu, Adrian-Tudor, and Vasile Manta. “Smart contracts for research data rights manage-
ment over the ethereum blockchain network.” Science and Technology Libraries 37.3 (2018):
21. Rahmadika, Sandi, Diena Rauda Ramdania, and Maisevli Harika. “Security Analysis on the
Decentralized Energy Trading System Using Blockchain Technology.” Jurnal Online Infor-
matika 3.1 (2018): 44-47.
22. Novo, Oscar. “Scalable Access Management in IoT using Blockchain: a Performance Evalu-
ation.” IEEE Internet of Things Journal (2018).
23. Sharma, Pradip Kumar, and Jong Hyuk Park. “Blockchain based hybrid network architecture
for the smart city.” Future Generation Computer Systems 86 (2018): 650-655.
24. Jiang, Yiming, et al. “A Cross-Chain Solution to Integrating Multiple Blockchains for IoT
Data Management.” Sensors 19.9 (2019): 2042.
25. Shen, Bingqing, Jingzhi Guo, and Yilong Yang. “MedChain: Efficient Healthcare Data Shar-
ing via Blockchain.” Applied Sciences 9.6 (2019): 1207.
26. Fan, Kai, et al. “Medblock: Efficient and secure medical data sharing via blockchain.” Journal
of medical systems 42.8 (2018): 136.
27. Chen, Yi, et al. “Blockchain-based medical records secure storage and medical service frame-
work.” Journal of medical systems 43.1 (2019): 5.
... Toward this end, some authors have proposed improved system models to utilise cache memory at edge nodes efficiently. However, some of these schemes only ensure the privacy and protection of IoT data but fail to guarantee the privacy and protection of users [158]. It would be interesting to conduct cutting edge research in this domain to improve the privacy and protection of network users. ...
... The smart contract code starts automatically when the contract trigger criteria are reasonably satisfied. Again, the loss of information asymmetry, resulting from the time difference in the entire wireless sensor network, could be mitigated by authenticating the malicious sensor node and recording it in the blockchain network in time [158]. However, model security in most blockchain-based security systems still poses a major threat that necessitates further investigation. ...
Full-text available
Wireless Sensor Networks (WSNs) are broadly applied for various applications in tracking and surveillance due to their ease of use and other distinctive characteristics compelled by real-time cooperation among the sensor nodes. In WSNs, security is becoming a critical issue, as the techniques for malicious node detection adopt a one-time, centralized decision-making approach. With this paradigm, errors are difficult to avoid, and reproducibility and traceability are challenging. Hence, malicious node discovery technologies in conventional WSNs cannot assure traceability and fairness of the detection method. Herein, this paper discusses an in-depth survey of a blockchain-based approach for malicious node detection, an exhaustive examination of the integration of blockchain techniques with WSNs (BWSN), and insights into this novel concept. This survey discusses the architecture, sector-wise applications, and uses of BWSN. Moreover, this survey describes malicious node detection based on BWSN in two parts: 1) the BWSN architecture for detecting the malicious nodes and 2) the smart contract aspects in malicious node detection. Next, this survey explains the contributions of blockchain for WSN data management, which involves online information aggregation and may include auditing, event logs, and storage for information analysis and offline query processing. This survey first presents the conventional WSN solutions then the blockchain-based WSN solutions for data management. Additionally, this survey discusses the contributions of blockchain for WSN security management. It first examines the centralized WSN models for security problems, followed by a discussion of the blockchain-based WSN solutions for security management, such as offering access control, preserving information integrity, guaranteeing privacy, and ensuring WSNs’ node longevity.
... However, to the best of our knowledge, this is the first time that blockchain and FL have been combined for vehicle networks. Previously researchers examined IoT and blockchain applications in vehicular networks [22,[27][28][29][30][31][32][33][34]. However, those surveys are not concerned with blockchain and FL applications in IoV networks. ...
Full-text available
The Internet of Things (IoT) revitalizes the world with tremendous capabilities and potential to be utilized in vehicular networks. The Smart Transport Infrastructure (STI) era depends mainly on the IoT. Advanced machine learning (ML) techniques are being used to strengthen the STI smartness further. However, some decisions are very challenging due to the vast number of STI components and big data generated from STIs. Computation cost, communication overheads, and privacy issues are significant concerns for wide-scale ML adoption within STI. These issues can be addressed using Federated Learning (FL) and blockchain. FL can be used to address the issues of privacy preservation and handling big data generated in STI management and control. Blockchain is a distributed ledger that can store data while providing trust and integrity assurance. Blockchain can be a solution to data integrity and can add more security to the STI. This survey initially explores the vehicular network and STI in detail and sheds light on the blockchain and FL with real-world implementations. Then, FL and blockchain applications in the Vehicular Ad Hoc Network (VANET) environment from security and privacy perspectives are discussed in detail. In the end, the paper focuses on the current research challenges and future research directions related to integrating FL and blockchain for vehicular networks.
... Os estudos secundários mais relevantes estão elencados na Tabela 1. Conforme pode ser constatado, as revisões sistemáticas encontradas não focam no uso sistemas de reputação integrando a tecnologia blockchain e redes veiculares. Foram também encontrados surveys [9,25,29,34,36], porém, estes não apresentam de fato uma investigação detalhada de sistemas de reputação utilizando a tecnologia blockchain em VANETs. Assim, estas observações evidenciam o diferencial e a relevância deste presente trabalho. ...
Conference Paper
Full-text available
Vehicular networks form an important pillar of current IntelligentTransportation Systems. Due to its specific characteristics, thesenetworks have been using reputation systems and or trust modelsto ensure security and trustworthiness. In addition, blockchainis a valuable technology that enables the development of thesesystems, addressing privacy, anonymity, and access control issues.This work aims to describe the results of the systematic literaturereviewon blockchain-based reputation systems.We compared someselected works and highlighted the adopted techniques and themain challenges.
... Many researchers have investigated the use and adaptation of the blockchain in various fields such as healthcare, supply chain, Internet of Things, wireless sensor network ..., as illustrated in Figure 1. [15] Fatima et al. in [14] presented a state of the art on blockchain applications for wireless sensor networks, VANETs, IoT and healthcare. They outlined the problems addressed and the proposed solutions. ...
... In previous energy efficient routing protocols [2,4,5,8,12,13,18,19,23,25,29,34,35] main components of energy consumption in WBAN are Transceiver unit(Transmit, receive and ideal), sensing unit (sense and actuate) and processing unit (display, aggregate and compute) shown in Fig. 2. In WBAN, there are two components of energy consumption, one is at body network and second one is at system network. In on-body, different heterogeneous sensors that can be wearable or implanted like blood pressure, ECG, EMG etc., are used for collecting vital signals of the patient. ...
Full-text available
Today’s era is the era of smart and remote applications exploiting advancement in sensors, cloud, Internet of things etc. Major application is in healthcare monitoring and support using wireless body area network (WBAN) in which sensor nodes sense vital physiological parameters and send to server through sink i.e. smart phone nowadays for seamless monitoring. The most significant issue in such applications is energy efficiency which leads to enhanced network life time that ensures uninterrupted seamless services. From source to sink data transmission may occur considering three different scenarios: source to sink single hop direct data transmission irrespective of in-between node distance, source to sink multi hop data transmission in which transmission range of source node is fixed at a threshold to find next forwarder node and transmission range of source node is incremented by affixed value until data gets transmitted to sink. In this work WBAN having different network configurations based on fixed or random positions of nodes have been simulated. Different scenarios with fixed and varying number of nodes are framed and simulated using MATLAB 2020a for performance evaluation of proposed algorithm in terms of energy consumption, network lifetime, path loss etc. due to data transmission from source to sink. Experimental results show that incremental approach is better than direct one in terms of energy consumption, path loss and network lifetime. While selecting transmission range of a source node, it is considered to keep Specific Absorption Rate (SAR) lower to reduce impact on human tissue.
The most advanced and emerging component of an intelligent transportation system (ITS) is the vehicular ad hoc network (VANET). Vehicles communicate with nearby vehicles or road side units (RSUs) in order to provide safety or non-safety information. This information containing vehicle ID, current position, speed and vehicle status is shared periodically among nearby vehicles. VANET provides tremendous benefits to drivers, but due to its inherent characteristics, it is important to address security and privacy issues before it can be fully adopted. It is required to authenticate the vehicles participating in the network and held responsible in case any type of misbehavior is encountered in the network. Traditional centralized security solutions are not suitable in VANET because of high speed of vehicles, minimal communication resources and delay sensitive applications. Blockchain is a decentralized and distributed computing platform that makes it easier to record and manage resources without relying on a centralized trusted authority. Therefore, blockchain based solution is expedient in VANET scenario which provides transparency, tamper resistance and immutableness. This paper aims to envision a comprehensive review on applications of blockchain in VANET security. We first present the introduction of VANET security and blockchain. Then, we conduct a literature review on the existing security solutions using blockchain in VANET by considering the technical issues and research problems. At last, we highlight some future research issues by reviewing the characteristics of both blockchain and VANET.
Full-text available
In this paper, a blockchain-based data sharing and access control system is proposed, for communication between the Internet of Things (IoT) devices. The proposed system is intended to overcome the issues related to trust and authentication for access control in IoT networks. Moreover, the objectives of the system are to achieve trustfulness, authorization, and authentication for data sharing in IoT networks. Multiple smart contracts such as Access Control Contract (ACC), Register Contract (RC), and Judge Contract (JC) are used to provide efficient access control management. Where ACC manages overall access control of the system, and RC is used to authenticate users in the system, JC implements the behavior judging method for detecting misbehavior of a subject (i.e., user). After the misbehavior detection, a penalty is defined for that subject. Several permission levels are set for IoT devices' users to share services with others. In the end, performance of the proposed system is analyzed by calculating cost consumption rate of smart contracts and their functions. A comparison is made between existing and proposed systems. Results show that the proposed system is efficient in terms of cost. The overall execution cost of the system is 6,900,000 gas units and the transaction cost is 5,200,000 gas units.
Full-text available
The Internet of Things (IoT) industry is growing very fast to transform factories, homes, farms and practically everything else to make them efficient and intelligent. IoT is applied in different resilient scenarios and applications. IoT faces lots of challenges due to lack of computational power, battery and storage resources. Fortunately, the rise of blockchain technology facilitates IoT in many security solutions. Using blockchain, communication between IoT and emerging computing technologies is made efficient. In this work, we propose a secure service provisioning scheme with a fair payment system for Lightweight Clients (LCs) based on blockchain. Furthermore, an incentive mechanism based on reputation is proposed. We use consortium blockchain with the Proof of Authority (PoA) consensus mechanism. Furthermore, we use Smart Contracts (SCs) to validate the services provided by the Service Providers (SPs) to the LCs, transfer cryptocurrency to the SPs and maintain the reputation of the SPs. Moreover, the Keccak256 hashing algorithm is used for converting the data of arbitrary size to the hash of fixed size. AES128 encryption technique is used to encrypt service codes before sending to the LCs. The simulation results show that the LCs receive validated services from the SPs at an affordable cost. The results also depict that the participation rate of SPs is increased because of the incentive mechanism.
Full-text available
In a research community, data sharing is an essential step to gain maximum knowledge from the prior work. Existing data sharing platforms depend on trusted third party (TTP). Due to the involvement of TTP, such systems lack trust, transparency, security, and immutability. To overcome these issues, this paper proposed a blockchain-based secure data sharing platform by leveraging the benefits of interplanetary file system (IPFS). A meta data is uploaded to IPFS server by owner and then divided into n secret shares. The proposed scheme achieves security and access control by executing the access roles written in smart contract by owner. Users are first authenticated through RSA signatures and then submit the requested amount as a price of digital content. After the successful delivery of data, the user is encouraged to register the reviews about data. These reviews are validated through Watson analyzer to filter out the fake reviews. The customers registering valid reviews are given incentives. In this way, maximum reviews are submitted against every file. In this scenario, decentralized storage, Ethereum blockchain, encryption, and incentive mechanism are combined. To implement the proposed scenario, smart contracts are written in solidity and deployed on local Ethereum test network. The proposed scheme achieves transparency, security, access control, authenticity of owner, and quality of data. In simulation results, an analysis is performed on gas consumption and actual cost required in terms of USD, so that a good price estimate can be done while deploying the implemented scenario in real set-up. Moreover, computational time for different encryption schemes are plotted to represent the performance of implemented scheme, which is shamir secret sharing (SSS). Results show that SSS shows the least computational time as compared to advanced encryption standard (AES) 128 and 256.
Conference Paper
Full-text available
The emergence of smart homes appliances has generated a high volume of data on smart meters belonging to different customers which, however, can not share their data in deregulated smart grids due to privacy concern. Although, these data are important for the service provider in order to provide an efficient service. To encourage customers participation, this paper proposes an access control mechanism by fairly compensating customers for their participation in data sharing via blockchain and the concept of differential privacy. We addressed the computational issues of existing ethereum blockchain by proposing a proof of authority consensus protocol through the Pagerank mechanism in order to derive the reputation scores. Experimental results show the efficiency of the proposed model to minimize privacy risk, maximize aggregator profit. In addition, gas consumption, as well as the cost of the computational resources, is reduced. Index Terms-Blockchain, consensus mechanism, proof of authority, privacy preserving and smart grid. I. INTRODUCTION Presently, because of the rapid growth of the world population and the technological innovations, a lot of energy is needed in a short period of time and during peak hours, and its effect increases the cost of production. Customers can, therefore, optimize their utilization based on the current energy demand and supply. As a result, demand response and dynamic pricing proposal are subject to privacy issues. In a smart grid, customers will share their hourly information load profile with a service provider only to allow a certain level of privacy to be maintained, which is a major barrier for customer participation. In order to efficiently aggregate customer data, while preserving their privacy, Liu et al. [1] propose a privacy-preserving mechanism for data aggregation. The proposed solution minimizes the cost of communication and computational overhead. However, a trusted environment is not considered. To achieve a trusted environment, several studies in [2]-[8] used blockchain as privacy-preserving mechanism for data aggregation; privacy protection and energy storage; secure classification of multiple data; incentive announcement network for smart vehicle; crowdsensing applications; dynamic tariff decision and payment mechanism for vehicle-to-grid. A survey concerning privacy protection using blockchain is discussed in [9]. The survey highlights all the existing
Full-text available
With the rapid development of the internet of things (IoT), traditional industries are setting off a massive wave of digitization. In the era of the Internet of Everything, millions of devices and links in IoT pose more significant challenges to data management. Most existing solutions employ centralized systems to control IoT devices, which brings about the privacy and security issues in IoT data management. Recently, blockchain has attracted much attention in the field of IoT due to its decentralization, traceability, and non-tamperability. However, it is non-trivial to apply the current blockchain techniques to IoT due to the lack of scalability and high resource costs. Different blockchain platforms have their particular advantages in the scenario of IoT data management. In this paper, we propose a cross-chain framework to integrate multiple blockchains for efficient and secure IoT data management. Our solution builds an interactive decentralized access model which employs a consortium blockchain as the control station. Other blockchain platforms customized for specific IoT scenarios run as the backbone of all IoT devices. It is equivalent to opening the off-chain channels on the consortium blockchain. Our model merges transactions in these channels for confirmation based on the notary mechanism. Finally, we implement a prototype of the proposed model based on hyperledge Fabric and IOTA Tangle. We evaluate the performance of our method through extensive experiments. The results demonstrate the effectiveness and efficiency of our framework.
Full-text available
Recently, Artificial Intelligence (AI) and blockchain have become two of the most trending and disruptive technologies. Blockchain technology has the ability to automate payment in cryptocurrency and to provide access to a shared ledger of data, transactions, and logs in a decentralized, secure, and trusted manner. Also with smart contracts, blockchain has the ability to govern interactions among participants with no intermediary or a trusted third party. AI, on the other hand, offers intelligence and decision-making capabilities for machines similar to humans. In this paper, we present a detailed survey on blockchain applications for AI. We review the literature, tabulate, and summarize the emerging blockchain applications, platforms, and protocols specifically targeting AI area. We also identify and discuss open research challenges of utilizing blockchain technologies for AI.
Full-text available
This work provides a systematic literature review of blockchain-based applications across multiple domains. The aim is to investigate the current state of blockchain technology and its applications and to highlight how specific characteristics of this disruptive technology can revolutionise "business-as-usual" practices. To this end, the theoretical underpinnings of numerous research papers published in high ranked scientific journals during the last decade, along with several reports from grey literature as a means of streamlining our assessment and capturing the continuously expanding blockchain domain, are included in this review. Based on a structured, systematic review and thematic content analysis of the discovered literature, we present a comprehensive classification of blockchain-enabled applications across diverse sectors such as supply chain, business, healthcare, IoT, privacy, and data management, and we establish key themes, trends and emerging areas for research. We also point to the shortcomings identified in the relevant literature, particularly limitations the blockchain technology presents and how these limitations spawn across different sectors and industries. Building on these findings, we identify various research gaps and future exploratory directions that are anticipated to be of significant value both for academics and practitioners.
The adoption of agricultural products traceability management based on Internet of Things (IoT) technology provides excellent benefits for the current food safety issues. The provenance data can demonstrate agricultural products movement process from the countryside to the dining table. However, the massive provenance data incurs an inefficient query. Meanwhile, the provenance data can be tampered deliberately which affect food safety. There are seldom reported approaches that can solve the above problem effectively. In this paper, we propose a data storage model based on Inter-Planetary File System (IPFS) and blockchain. First, IPFS is used to store video, images, and real-time monitoring data reported from the sensors. Then, in order to avoid a malicious user in case of data faking attack, we exploit the blockchain to store the IPFS hash address of the provenance data. Based on that, we design an authentication mechanism based on blockchain. It can verify the data and ensures effective data security. The experimental results show that the proposed approach can outperforms the existing methods. © Computer Society of the Republic of China. All rights reserved.
Blockchain technologies have recently come to the forefront of the research and industrial communities as they bring potential benefits for many industries. This is due to their practical capabilities in solving many issues currently inhibiting further advances in various industrial domains. Securely recording and sharing transactional data, establishing automated and efficient supply chain processes, and enhancing transparency across the whole value chain are some examples of these issues. Blockchain offers an effective way to tackle these issues using distributed, shared, secure, and permissioned transactional ledgers. The employment of blockchain technologies and the possibility of applying them in different situations enables many industrial applications through increased efficiency and security; enhanced traceability and transparency and reduced costs. In this paper, different industrial application domains where the use of blockchain technologies has been proposed are reviewed. The paper explores the opportunities, benefits, and challenges of incorporating blockchain in different industry applications. Furthermore, the paper attempts to identify the requirements that support the implementation of blockchain for different industry applications. The review reveals that several opportunities are available for utilizing blockchain in various industry sectors; however, there are still some challenges to be addressed to achieve better utilization of this technology.
Blockchain technologies is one of the most popular issue in recent years, it has already changed people's lifestyle in some area due to its great in uence on many business or industry, and what it can do will still continue cause impact in many places. Although the feature of blockchain technologies may bring us more reliable and convenient services, the security issues and challenges behind this innovative technique is also an important topic that we need to concern.