IOT Security Issues Via Blockchain: A Review Paper

Abstract

In the past few years block chain has gained lot of popularity because blockchain is the core technology of bitcoin. Its utilization cases are growing in number of fields such as security of Internet of Things (IoT), banking sector, industries and medical centres. Moreover, IoT has expanded its acceptance because of its deployment in smart homes and city developments round the world. Unfortunately, IoT network devices operate on limited computing power with low storage capacity and network bandwidth. Thus, they are extra close to attacks than other end-point devices such as cell phones, tablets, or PCs. This paper focus on addressing significant security issues of IoT and maps IoT security issues in contradiction of existing solutions found in the literature. Moreover issues that are not solved after implementation of blockchain are highlighted.

Full text

IOT Security Issues Via Blockchain: A Review Paper
Abid Sultan
Department of CS & IT
University of Sargodha, Sub-
Campus Bhakkar, Pakistan
+92-453-220072
Abidsultan006@gmail.com
Muhammad Azhar Mushtaq
Department of CS & IT
University of Sargodha, Sub-
Campus Bhakkar, Pakistan
+92-453-220072
Azhar.mushtaq@uos.edu.pk
Muhammad Abubakar
Department of CS & IT
University of Sargodha, Sub-
Campus Bhakkar, Pakistan
+92-453-220072
Abubakar.shibly@gmail.com
ABSTRACT
In the past few years block chain has gained lot of popularity
because blockchain is the core technology of bitcoin. Its
utilization cases are growing in number of fields such as security
of Internet of Things (IoT), banking sector, industries and
medical centres. Moreover, IoT has expanded its acceptance
because of its deployment in smart homes and city developments
round the world. Unfortunately, IoT network devices operate on
limited computing power with low storage capacity and network
bandwidth. Thus, they are extra close to attacks than other end-
point devices such as cell phones, tablets, or PCs. This paper
focus on addressing significant security issues of IoT and maps
IoT security issues in contradiction of existing solutions found in
the literature. Moreover issues that are not solved after
implementation of blockchain are highlighted.
CCS Concepts
• Computer systems organization → Embedded and cyber-
physical systems → Embedded systems.
• Networks → Network properties → Network reliability
Keywords
Blockchain, IoT, Network Security, Data security, LLNs &POW
1. INTRODUCTION
In today’s era, technologies have revolutionized the living
standard of our society. This is often because of innovation in
communication and semiconductor technologies, which permit
devices to be connected over a network and alter the way of
connectivity between machines and humans. Such a trend is
usually noted as Internet-of-Things (IoT) [15].
With the fast rise of brilliant devices and high-speed networks,
the IoT has gained wide acceptance and fame because it uses the
standard called low-power lossy networks (LLNs). These LLNs
have the potential to use the limited resource by consuming very
low power [1] [2]. The devices in IoT may be controlled
remotely to perform the specified function. The data sharing
among the devices takes place through the network that uses the
standard protocols of communication. The well-connected
devices or “things” vary from easy wearable accessories to huge
machines which contain detector (Sensor) chips [14].
However, as it becomes popular the connectivity between
devices is increasing, and also the computing infrastructure can
become additionally complicated. This complication can give a
rise to vulnerabilities for the cyber-attacks. In IoT, the physical
devices are placed in unsecured environments which could be
defenceless from hackers thus giving them the opportunity to
alter the information that transmits over the network. Therefore,
device authorizations and information root would be a vital issue.
In last few years blockchain has begun as the technology that
have many characteristics to solve different issues faced by IoT
network devices. Blockchain keeps a distributed database of
records. In which proof of work between the network nodes is
completely deprived of a
third party. This will help in solving the problem of single point
of failure. Network transaction records are immutable and can be
founded via the history of IoT network which finally helps to get
the attraction by trust of public in the IoT network. This Public
trust have a vital role for the public financial transactions,
introductory for a new world of distributing economy in the
Internet of Things domain [8] [14] [3] [18].
The blockchain is sequences of blocks that hold all transaction
record occuring in a blockchain network. As described in
figure.1 each block contains block header and block body/
transaction counter. Block header contains the following;
1. Block version which indicates the software version
and validation rules.
2. Merkle Tree root hash represents the hash value of
the transaction and summary of all transaction.
3. Timestamp consists of current universal time since
January 1970.
4. N-Bits define the number of bits required for
transaction verification.
5. Nonce is any 4-byte number which starts from 0 and
increases for every hash of the transaction.
6. Parent block hash holds the hash value which
indicates the previous block.
Transaction counter is capable of covering all the transaction and
a maximum number of the transaction depends upon the block
size [12].
Blockchain technology referred as a public ledger and all
completed transactions are recorded in a list of blocks. This
chain of blocks grows as new blocks are added to chain
continuously. Public key cryptography and distributed consensus
algorithms implemented for user security. The blockchain
technology has key characteristics of decentralization,
persistency, anonymity, and auditability. With these
characteristics, blockchain can save the cost and increases the
effectiveness [12].
This paper is ordered as follows. Section 2 covers the
Blockchain properties where as section 3 highlights its
characteristics. Different security necessities and issues are
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DOI: https://doi.org/10.1145/3320154.3320163
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covered in section 4 and section 5 provides the solution of
security issues using blockchain. Section 6 describes the
problems that are not solved by blockchain. Finally in Section 7
conclusion and future work is presented.
Figure 1. Block Architecture [12].
2. BLOCKCHAIN PROPERTIES
2.1. Blockchain Working Steps
1. Nodes communicate with the blockchain network via a
combination of private & public keys. Theuserusesitsown
private key to digitally sign its own transactions and then can
access the network via the public key. Each signed transaction is
broadcast by a node that makes the transaction [3].
2. The transaction is then verified by all nodes within the
blockchain network except the node that makes the transaction.
During this step, any invalid transactions are discarded. It’s
known as verification.
3. Mining is the third step in which every legitimate transaction
is collected by the network nodes during a fixed time into a
block and implements a proof-of-work to find a nonce for its
block. Once a node finds a nonce, it broadcasts the block to all
participating nodes [4].
4. Each node collects a newly generated block and confirms
whether the block contains (a) legal transactions and (b) declares
the accuracy of parent block by utilizing the hash value. After
the completion of confirmation, nodes will add the block to the
blockchain and apply the transactions to bring the blockchain
up-to-date. In case, if the block is not confirmed, the projected
block is rejected. This ends the existing mining round [3].
2.2. Verification
Blockchain technology ensures the elimination of the duplication
issues by taking assistance from asymmetric cryptography which
contains a public and a private key. The private key is kept
secret from other nodes whereas the public key is shared among
all other nodes [5]. Moreover, the transaction (step 1) is digitally
signed by a node that creates the transaction which is
broadcasted to the entire blockchain network. All receiving
nodes will verify the transactions by decrypting the signature
with a public key of the initializing node. The transaction is
verified by the verification of signature which indicates the
initializing node is not modified.
2.3. Proof-of-Work (POW)
The proof-of-work (figure 2) contains the process of finding a
value that is hashed with Secure Hash Algorithm 256. The
typical work needed is exponential within the variety of zero bits
needed and confirmed by running the hash algorithm. In an
exceeding blockchain network, all nodes implement the proof-
of-work for every mining process by increase a nonce value
within the block till a value is founded that offers the block’s
hash desired bits. Once the system unit effort has been spent to
satisfy the proof-of-work, the block can't be modified until not
redoing the work.
Blockchain feature distributed IoT information management can
provide users the choice of sharing the information with third
party entities. The target is to supply a distributed information
access model for IoT, that ensures that user-data isn't assigned to
centralized entities or corporations [4].
Figure 2. Proof of Work.
3. CHARACTERISTICS OF BLOCKCHAIN
3.1. Decentralization
In centralized transaction processing environment, each
transaction needs to be validated through the centralized trusted
party (e.g., banking system), that result into high-cost and low
performance at the central point. With respect to the centralized
IoT model, the third party is no longer needed in the blockchain.
Consensus algorithms in blockchain are used to maintain data
integrity and consistency [12].
3.2. Persistency
Once a transaction record is validated by a miner node (special
nodes that validate the transaction) in a blockchain network its
copy is broadcast on the entire network and that record is not
deleted or rollback from entire blockchain [12].
3.3. Anonymity
In Blockchain, nodes interact with the network using a public
key that addresses the node on the entire blockchain network by
keeping the real identities of the user as a secret [12].
3.4. Security
Blockchain uses the asymmetric cryptographic technique to
secure the entire network. Asymmetric or public key
cryptography contain 2 keys one public key and second private
key. The public key is used by the node to address the
blockchain network and the private key is used by the node to
sign the transaction that it initiates. The identity of transaction
creator node is verified by using its public key.
3.5. Scalability or More Addressing Space
AS scalability is concerned blockchain contains 160-bit address
space as compared to 128 bit in IPv6. These 160-bits are
generated by ECDSA (Elliptic Curve Digital Signature
Algorithm). Blockchain has 4.3 billion more Addresses over
IPv6 [8].
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3.6. Resilient Backend
Every distributed node within the blockchain IOT network
maintains a replica of the whole ledger. This helps in
safeguarding the network form any potential failures and attacks
[10].
3.7. High Efficiency
Since the transaction removes the involvement of the third party
and may proceed in low-trust condition, the time spent to verify
a transaction will be decreed whereas the efficiency will be
increased [11].
3.8. Transparency
Changes made to public blockchain network are publicly
viewable by all participants in the network. Moreover, all
transactions are immutable, meaning they cannot be altered or
deleted [9].
3.9. Smart Contract
The smart contract is one of the most efficient aspects of the
Ethereum introduced by Nick Szabo in 1994 [7]. Using smart
contract programs are written in which access rights and
different policies are defined. Many programming languages are
supported by Ethereum to write smart contracts such as Solidity
[13].
4. SECURITY NECESSITIES FOR IOT
OR ISSUES
4.1. Data Privacy
Because of a diversified integration of services and network, the
data recorded on a device is vulnerable to attack by
compromising nodes existing in associate IoT network.
Moreover, an attacker can access the data without owner
permission [14].
4.2. Data Integrity
In a centralized client-server model, the attacker may gain
unauthorized access to the network and change the original data
or information and forward it. For example, X sends data to Y,
Z the middle guy might get data first and forward the data after
modification [14].
4.3. Third Party
Data collected in a centralized environment is stored and
controlled by a third centralized entity that may miss use this
data or provide it to someone else.
4.4. Trusted Data Origin
In IoT environment, it is difficult to know the origin of data and
data might be altered during the transmission by anyone.
4.5. Access Control
Access control is one off the main issue in IoT network. It is
difficult to define in IoT network that which node has the right
to access and perform a different function with data.
4.6. Single Points of Failure
Continuous growth of centralized networks for the IoT based
infrastructure could expose single-points-of-failure. As all data
of the entire network is stored and verified by a central authority
in the case, if the central point fails or goes down the whole
network is disturbed [14].
4.7. Scalability
IoT connects a large number of sensors and other devices for
information sharing and a large number of applications via the
internet. It challenges the structure and the rapid growth of the
system to meet scalability.
4.8 Illegal use of Personal Data.
IoT device are basically sensors and implanted chips that gather
individual, important information and convey it through the
internet. The gathered information is stored in a central database
of any firm. This data exposes the personal performance of users;
confidentiality of users is at risk as firms might use the data
illegally [16] [6]. An example of such confidentiality misuse is
PRISM Surveillance program.
4.9 IOT Network Information Sharing.
The information gathered by IoT network devices are recorded
distinctly for the purpose of analysis. Information sets may
contain IoT devices network data load or their functioning logs.
To confirm the efficiency of tools and tests, open accessibility of
information plays a vital role. So, every time these information
sets are openly shared their integrity is significant.
5. BLOCKCHAIN SOLUTIONS FOR IOT
5.1. Data Integrity
The blockchain is a peer-to-peer network in which all nodes
have the same copy of records. When a transaction is initiated,
initiator node signs the transaction with its private key and sends
to other nodes for validation. All other miner nodes take part
invalidation process and try to find nonce. The node which finds
the nonce first has the right to validate and get a reward.
Moreover, the newly created block will be broadcasted to all
other nodes of the entire network. Once the record is loaded in
blockchain it cannot be modified or deleted [10].
5.2. Data Privacy
Consortium blockchain used to provide data privacy in a
blockchain network. As in figure.3,nodes used for a particular
purpose are combined together to form a private
network/sidechain. Each sidechain is responsible to manage its
own IoT data. Nodes that are participating in one sidechain are
not allowed to take part in the validation process of other
sidechains. In order to access the data of consortium blockchain
network the node first need to register and become part of that
sidechain network. Consortium blockchain has access control
and prevents unauthorized access [6].
Figure 3. Consortium Blockchain Network.
5.3. Addressing Space
Blockchain contains 160-bit address space as compaired to 128
bit in IPv6. These 160-bits are generated by ECDSA (Elliptic
Curve Digital Signature Algorithm). Blockchain has 4.3 billion
more addresses than IPv6 thus providing more addressing
spacing than IPV6 address [8].
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5.4. Trusted Accountability.
Every operation record must be uploaded to the blockchain
network. This gives every operation an identity and each
operation is traceable. When an abnormal behaviour is detected
in an entity, blockchain will be used for an additional
investigation [10].
5.5. Fault Tolerance
Decentralized devices are less likely to fail accidentally because
they rely on many separate components. The blockchain is a
point to point decentralizing network, in it, every device has the
same copy of a record that’s why the failure of a single node has
no effect on the network. So, blockchain prevents from a single
point of failure.
5.6. Trusted Data Origin
In order to track data in the blockchain network, a unique id is
assigned to each IoT device. Data collected from a device is
associated with its id and after calculating a hash on data, the
data is submitted to the entire network. This becomes the basis
for trusted data origin [10].
5.7. Removing Third-Party Risks
Blockchain technology makes the devices capable of performing
operations without the intermediary or third party, thus making it
risk-free from a third party [4].
5.8. Access Control
By using smart contract, programs for blockchain can be
developed in which access rights and different policies are
defined. Example a rule is set when the meter reaches to 135
KW, devices will enter in energy saving mode [7].
5.9 Illegal Use of Personal Data.
Illegal use of personal data can be prohibited with the use of
blockchain. As Blockchain Peer to Peer (P2P) storing systems
can verify and record all actions accomplished on IoT network
data [16]. The aim is to deliver decentralized storage wherever
operators can have command over their data as an alternative of
any centralized intermediary authority. So the privacy is more
stretched to numerous levels [6] where ‘Consortium blockchain’
for IoTs is proposed.
5.10 IOT Network Information Sharing.
As the size of IOT network information sharing is increasing,
thus the fundamental storage cost will also increase. So
information sets are kept in distant origins and a centralized
server is preserved which will lonely kept the references to these
origins. Moreover Blockchain is used to keep RIM (Reference
Integrity Matrix) of information set. As the Blockchains have
Immutability feature, and accessibility of the RIM with all IoT
network devices in Blockchain, ensured the Integrity of RIM.
Every time an obligatory Information Set is taken from the
origin, its Integrity can be confirmed by comparing its RIM
being maintained on Blockchain [17].
In Table 1 characteristics of blockchain are highlighted through
which problems of IoT can be tackled.
6. BLOCKCHAIN IMPLEMENTATION
PROBLEMS.
Anonymity
Blockchain is a distributed network; anonymity is significant to
protect privacy. Appropriately, blockchain provides
pseudonymity means the users don’t have a real-world ID. The
users have a Public key which is used to achieve transactions on
this distributed network. Using this ID a user can be found via a
combination of these Ids and IP addresses related with them.
Moreover, when a user uses more than one Public key it can be
traced by checking whether the different addresses belong to the
same user. Solution to the Anonymity is a future work [16].
7. CONCLUSION
This paper aims to present the literature review on Blockchain
and Internet of Things and emphasised issues linked to an IoT
atmosphere. IoT is the next immerging technology with the rise
of high-speed network and intelligent network devices.
Unfortunately, IoT devices are more prone to attacks and unable
to protect themselves. In this paper, the different properties and
characteristics of the blockchain network are highlighted such
order to remove the issues in IoT. Moreover issues that are not
solved after implementation of blockchain are highlighted.
7.1 Future Work
We further aim to practically implement blockchain
properties on the internet of things for monitoring, error
discovery, and automatic fault correction in high critical
IoT systems. Moreover, simulation-based performance
assessment can be conduct to demonstrate the scalability
and effectiveness of the blockchain-based solutions.
Furthermore, as IoT devices are in openly reachable areas
and actually below the control of an opponent, a
blockchain based solution can be implemented that will
assure the safety and confidentiality of the information kept
in the devices. This will also address in decreasing the
option of the hardware and software of an IoT device
from being compromised if the device is accessible to
everyone.
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Table.1 IoT issues and Blockchain characteristics that solve them
IOT
Issues
Blockchain Characteristics
Decartelization
Persistency
Anonymity
Scalability
or More
Addressing
Space
Resilient
Backend
High
efficiency
Transparency
Smart
contract
Data
Privacy
✓
✓
✓
Data
Integrity
✓
✓
✓
Third party
✓
✓
✓
Trusted
Data
Origin
✓
✓
✓
Access
control
✓
✓
✓
Single
Points of
Failure
✓
✓
✓
Scalability
✓
Illegal use
of Personal
Data
✓
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8. REFERENCES
[1] L. Atzori, A. Iera and G. Morabito (2010) ‘The Internet of
Things: a survey’, Computer Networks 54 2787–2805.
[2] D. Giusto, A. Iera, G. Morabito and L. Atzori (2014) ‘The
Internet of Things’, 20th Tyrrhenian Workshop on Digital
Communication, Springer Publishing Company,
Incorporated.
[3] K. Christidis and M. DevetsikIoTis, (2016) ‘Blockchains
and Smart Contracts for the Internet of Things,’ IEEE
Access, vol. 4, pp. 2292–2303.
[4] S.Nakamoto.(2008).’Bitcoin:A.PeertoPeer.electroniccashs
ystem,’https://bitcoin.org/bitcoin.pdf.
[5] M. Pilkington. (2016).’Blockchain technology: Principle
and applications,’ Research Handbook on Digital
Transformations.
[6] M.S. Ali, K. Dolui and F. Antonelli, (2017) ‘IoT data
privacy via blockchains and IPFS’ International
Conference on the Internet of Things (ACM, New York).
[7] M. Gord,(2016), Smart Contracts Described by Nick
Szabo 20 Years ago now becoming Reality, Bitcoin
Magazine.
[8] A. M. Antonopoulos, (2014). ‘Mastering Bitcoin. First
Edition’. O’Reilly Media,USA.
[9] T. Chollet, J. Castiaux, M.Bruneton and L.
Sainlez(2013),(2015),(2016),’Continuous interconnected
supply chain using blockchain and internet of things
supply chain traceability’ , deloitte blockchain.
[10] X.Liang, J.Zhao, S.Shetty and, D.Li, (2017) ,‘Towards
data assurance and resilience in IoT using blockchain’,
Conference Paper.
[11] Yu Zhang and Jiangtao Wen (2015), ‘An IoT electric
business model based on the protocol of bitcoin’. ICIN.
IEEE, pp. 184–191.
[12] Z. Zheng, S. Xie, H. Dai, X. Chen and H. Wang (2017),
‘An overviewof blockchain technology: Architecture,
consensus,and future trends.’,Big Data (Big DataCongress)
IEEE International.
[13] Seyoung Huh, Sangrae Cho and Soohyung Kim
(2017),’Managing IoT Devices using Blockchain
Platform’, ICACT2017 February 19 ~ 22.
[14] M.A. Khan and K. Salah (2017) ‘IoT security: Review,
blockchain solutions, and open challenges’, Future
GenerationComputer.Systems,
https://doi.org/10.1016/j.future.2017.11.022
[15] M. Banerjee, J. Lee and K.-K.R. Choo (2017),’A
blockchain future to Internet of Things security: A
position paper’, Digital Communications and
Networks,doi: 10.1016/ j.dcan.2017.10.006.
[16] M. Conoscenti, D. Torino, A. Vetr, D. Torino, and J. C.
De Martin , (2016) ‘Blockchain for the Internet of
Things : a Systematic Literature Review,’ IEEE/ACS 13th
International Conference of Computer Systems and
Applications (AICCSA)
[17] M Banerjee, J. Lee, and K. K. R. Choo (2018). ‘A
Blockchain future for internet of things security: a
position paper,’ Digit. Commun. Networks, vol. 4, no. 3,
pp. 149–160.
[18] Swan, (2015). ‘Blockchain Blue Print for a new economy.
First Edition’ O’Reilly Media,USA.
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