A framework of blockchain-based secure and privacy-preserving
E-government system
Noe Elisa
1
•
Longzhi Yang
1
•
Fei Chao
2
•
Yi Cao
3
Published online: 3 December 2018
Ó The Author(s) 2018
Abstract
Electronic government (e-government) uses information and communication technologies to deliver public services to
individuals and organisations effectively, efficiently and transparently. E-government is one of the most complex systems
which needs to be distributed, secured and privacy-preserved, and the failure of these can be very costly both economically
and socially. Most of the existing e-government systems such as websites and electronic identity management systems
(eIDs) are centralized at duplicated servers and databases. A centralized management and validation system may suffer
from a single point of failure and make the system a target to cyber attacks such as malware, denial of service attacks
(DoS), and distributed denial of service attacks (DDoS). The blockchain technology enables the implementation of highly
secure and privacy-preserving decentralized systems where transactions are not under the control of any third party
organizations. Using the blockchain technology, exiting data and new data are stored in a sealed compartment of blocks
(i.e., ledger) distributed across the network in a verifiable and immutable way. Information security and privacy are
enhanced by the blockchain technology in which data are encrypted and distributed across the entire network. This paper
proposes a framework of a decentralized e-government peer-to-peer (p2p) system using the blockchain technology, which
can ensure both information security and privacy while simultaneously increasing the trust of the public sectors. In
addition, a prototype of the proposed system is presented, with the support of a theoretical and qualitative analysis of the
security and privacy implications of such system.
Keywords E-government systems
Blockchain technology Cybersecurity Privacy Decentralized systems
1 Introduction
The wide availability of internet has motivated different
countries around the world to exploit technologies as a
means of communication and services exchange between
citizens and other affiliates. E-government users enjoy the
online services without leaving their comfortable homes,
evading long queues in public offices whilst saving time
and transportation costs, and at the same time the service
providers can deliver services more effectively and effi-
ciently. Generally speaking, government networks can
communicate to each other better than business networks,
because most of them are connected for transferring
information to the public without competition. In the
future, the number of devices using e-government services
will increase dramatically due to the fast evolution of smart
homes, internet of things (IOT), smart cities, and other
interconnected networks [
1
,
2
]. According to the United
Nation e-government survey, 2014 [
3
], almost every gov-
ernment around the world is currently providing its citizens
and other stakeholders e-services via websites and mobile
applications.
E-government systems collect, store and process a sig-
nificant amount of confidential information about citizens,
employees, customers, products, researches, financial
& Longzhi Yang
longzhi.yang@northumbria.ac.uk
Noe Elisa
noe.nnko@northumbria.ac.uk
1
Department of Computer and Information Sciences,
Northumbria University, Newcastle upon Tyne NE1 8ST, UK
2
Cognitive Science Department, Xiamen University, Xiamen,
People’s Republic of China
3
Technology Department of Nanjing Customs District,
Nanjing, People’s Republic of China
123
Wireless Networks (2023) 29:1005–1015
https://doi.org/10.1007/s11276-018-1883-0
(0123456789().,-volV)(0123456789().,-volV)
status amongst others, using electronic computers. The
compromise of such information usually leads to the loss of
users’ trust and confidence, opportunities, and financial
advantages, etc [
4
]. It has been found that more than 80%
of e-government web sites around the globe were vulner-
able to cross-site scripting (XSS) and structured query
(SQL) injection due to the lack of proper authentication
mechanism applied to input data from users [
5
]. Recently,
many nations around the world have experienced a great
threat from denial of service attacks (DoS) and malware
targeting their networks [
6
]. For instance, the U.S. gov-
ernment suffered one of the largest e-government attacks in
2015, causing the leak of over 4 million government
employees’ confidential information, including security
clearance information, social security numbers, identities
and passwords [
7
]. According to the report in [
8
], in 2016,
the Tanzania government was hit by cyber-terrorists,
technology spies, hackers and digital fraudsters leading a
loss around 85 millions US dollars. In addition, more than
1500 user accounts in Singapore were hacked in the gov-
ernment platform in 2014, where hackers gained access to
creating new businesses and apply for work permits [
7
].
It is therefore of significant importance to ensure the
security, privacy, confidentiality, integrity and availability
of e-government systems. The existing e-government sys-
tems, such as e-government websites and eIDs manage-
ment systems [
9
,
10
], are centralized where one or
duplicated central servers and databases store and provide
information to users. The centralized management and
validation system is likely to suffer from a single point of
failure and makes the system a target to cyber attacks such
as DDoS, DoS and malware. Any e-government system
will remain vulnerable to privacy and security breaches if
better security technology and countermeasures are not
developed and available to combat these threats in the
future.
The blockchain technology has appeared to be one good
solution to provide a secure decentralized environment for
information exchange [
11
,
12
]. Although it was originally
introduced for exchanging digital currency as its underly-
ing technology, it has found security and privacy applica-
tions in many other areas, such as Internet of Things (IoTs)
[
13
], smart home [
14
], smart city [
1
], educational systems
[
15
], and healthcare [
16
]. While governments around the
world have not fully adopted the blockchain technology in
the public sectors, many countries have initiated block-
chain projects to explore the potential of blockchain tech-
nology in offering public services to individuals [
17
]. Each
of these projects usually focuses on a particular service, for
example e-residency, e-health, land registry etc; they are
still in their early stages and no common framework has
been proposed for blockchain technology integration
within the e-government systems [
17
]. In addtion, each of
these countries is developing their own blockchain frame-
work. Different blockchain systems from different coun-
tries lead to difficulties to communicate out of their
network for international information exchange.
This paper presents a framework and prototype of
blockchain-based secure and privacy-preserving e-govern-
ment system, which can be adopted by any government for
the purpose of ensuring both security and privacy while
simultaneously increasing trust in the public sector. The
system is made of a peer to peer network of e-government
devices (nodes) and user’s devices. Briefly, any new
e-government device or individual device joining the sys-
tem will be reviewed by the existing peers of the network
and one of the peer is elected to set up a network node and
blockchain address of a new device. When a new user
attempts to register with the system through a device or one
of the government departments, the user is assigned with a
user ID and a blockchain wallet for collecting and storing
his/her transaction. By doing so, e-government users can
submit and access their records from anywhere and
everywhere, using their IDs and blockchain addresses. This
paper has also analysed and evaluated the security and
privacy implications of the proposed system in public
sectors using theoretical and qualitative analysis.
The reminder of the paper is structured as follows.
Section
2
briefs the background technologies on the
blockchain and e-government systems. Section
3
intro-
duces the proposed e-government framework and proto-
type. Section
4
discusses the security and privacy
implications of the proposed system, and Sect.
5
concludes
the paper and outlines the future research directions.
2 Background
The background technologies on the blockchain and
e-government systems are reviewed in this section.
2.1 Blockchain technology
Blockchain is a peer to peer (p2p) distributed database (i.e.,
ledger) maintaining a list of continuously growing records
called blocks that are linked and secured usually using
public key cryptography [
11
]. By the blockchain technol-
ogy, new information is added to a block and becomes
available to all nodes in a distributed network, rather than
adding to the centralized database in the traditional cen-
tralized system. Each block in a blockchain is identified by
a hash value generated by usually using the secure hash
cryptographic algorithm-256bits (SHA256) [
11
]. The hash
value of a current block header (parent) is linked and stored
in the next block (child) as depicted in Fig.
1
[
18
]; there-
fore, if there is an alteration in any block’s content, its hash
1006
Wireless Networks (2023) 29:1005–1015
123
will also be changed accordingly and this change will be
propagated throughout the network to invalidate that block
[
11
]. Based on this mechanism, the blockchain technology
does not require an intermediary or trusted third party as it
is decentralized and distributed. The blockchain partici-
pants have private keys assigned to them to digitally sign
and validate the transactions they make.
As shown in Fig.
1
, a block is composed of a header
containing the meta data, and a long list of transactions
performed in that block. The block header typically con-
tains the timestamp, nonce, version and proof of difficulty.
The timestamp indicates the time that the block was cre-
ated; the nonce is a random number generated by the
consensus algorithm to compute the hash value of a block;
the version indicates the version number of the blockchain;
and the proof of difficulty is a generated hash value which
must be less than the current target hash value.
The first block, known as a genesis block, is hardcoded
by embedding some random data into the blockchain
application [
11
]. Although each block has only one parent
and one child, a valid block may have two or more children
temporarily created when two or more nodes (network
peers) are added to a block at the same time leading to two
or multiple branches from the same parent [
18
]. This sit-
uation is usually called ‘fork’ and is eliminated by taking
the chain whichever becomes longer than the others as a
valid blockchain, and making all other shorter ones invalid
(orphan), with a two-branch situation demonstrated in
Fig.
2
. It is possible that the formed branches have the same
length; in this situation, the process of adding new blocks
continue for all the to-be-validated chains until one branch
becomes longer than the others thus valid.
Within a block, all the transactions are linked together
using a merkle tree [
11
]. A merkle tree is an upside down
binary tree used by the blockchain technology to sum-
marise all the transaction in a block. To construct a merkle
tree, a pair of transactions are hashed recursively until they
form only one root node at the top of the tree termed as the
merkle root [
11
], as shown in Fig.
3
. More precisely, a
merkle root is the hash of all the transactions that make up
a block in a blockchain network. Any tiny modification of
the data will change the merkle root hash leading to an
invalid record. The most common cryptographic hash
algorithm used to construct a merkle tree is the secure hash
algorithm 256-bits (SHA256). If there is an odd number of
transactions, the last transaction hash is duplicated to create
an even number of transactions thus ending up with a
balanced tree.
Nodes in the blockchain network run a consensus
algorithm to validate transactions. There are several con-
sensus algorithms (protocols) available for the blockchain
technology, such as proof of work (PoW), proof of stake
(PoS), delegated proof of stake (DPoS), and proof of dif-
ficulty (PoD) [
18
,
19
]. For instance, Bitcoin employs the
PoW while Ethereum and Bitshare implement PoS and
DPoS, respectively [
19
]. In PoW, miner nodes which want
to add (mine) a new block to the blockchain network must
first solve a difficult mathematical puzzle which requires
great computational power. The miner who solves the
puzzle adds a new block and gets rewards in bitcoins [
18
].
Unlike the PoW, with the PoS, a node which creates a
new block is chosen deterministically depending on its
stake (wealth) [
19
]. PoS saves energy that is required in
PoW to solve the mathematical puzzle, and only the wealth
of a node (validator) is required to validate the new
transactions and blocks. The DPoS attempts to solve the
consensus problem using delegates [
19
]. DPoS uses a real
time voting and reputation system to create a panel of
limited trusted delegates who will witness and validate the
blocks. The witnesses have the rights to create blocks and
add them to the blockchain network, in addition to prohibit
malicious nodes from participating in adding blocks.
Principally, in PoS and DPoS, stakeholders of the network
shares are not expected to deliberately make bad decisions
for the network.
Blockchain network can be permissioned or permis-
sionless [
20
]. A permissionless network or public block-
chain allows any user to create a personal address, join the
Fig. 1 An example ledger with details of blocks
Fig. 2 Blockchain validation for the fork situation
Fig. 3 An illustration of the merkle tree
Wireless Networks (2023) 29:1005–1015
1007
123
network, and participate in consensus, whilst a permis-
sioned or private network only allows a number of
restricted nodes to join.
2.2 E-government systems
E-government services can typically be categorized into 3
groups: government to government (G2G), government to
citizen (G2C), and government to business (G2B) [
21
].
G2G offers an online interaction between government
departments, authorities, organisations and other govern-
ments to disseminate information among themselves using
the internet. G2C and G2B allow citizens and businesses to
interact with the government to get online services such as
filing property tax, filing income tax, extending/renewal of
visa, passport and licenses, online voting, e-procurement
application, etc.
Every e-government department ensures that only
authorized users can get access to individual’s confidential
information. In additional to security and privacy, another
important factor to consider during e-government imple-
mentation is to build a trustable system that users can rely
on [
22
]. Security and privacy assurance in e-government
systems plays a critical role in increasing trustness between
different departments within the government as it guaran-
tees confidentiality, integrity, and privileged access of
sensitive information. Typical attacks that e-government
system faces include packet sniffers, probes, malware,
DDoS, phishing etc [
23
,
24
]. Due to cyber warfare, there
are other new motivations for attacks such as political
differences, extortion, cyber terrorism, and even contests
for the supremacy which can occur within a nation or
between different nations [
6
].
Different non-technical e-government security maturity
models have been proposed for guiding and benchmarking
the security implementation of the e-government system.
For instance, a comprehensive e-government information
security maturity model for guiding the inclusion of secu-
rity in e-government systems was reported in the work of
[
21
]. This model focuses only on the organisation’s secu-
rity mechanisms setting, security evaluation, security pol-
icy setting and information security awareness to users, but
it lacks guidance for built-in security that can ensure
e-service security and privacy.
Commonly, the security and privacy of e-government
systems are provided using firewalls, intrusion detections
systems (IDSs), public key infrastructure (PKI) and anti-
virus mechanisms [
2
]. Various artificial intelligence tech-
niques have been employed in the implementation of IDSs
that can also be used by e-government systems [
25
–
30
]. In
addition to these common solutions, one hardware solution
to e-government security issues is the use of eID system
[
31
] for identification, authentication, confidentiality and
integrity of users’ information. An eID system uses a smart
card which includes a chip to store cardholder’s personal
data including date of birth, civil status, parenthood, cur-
rent and past addresses, etc, in additional to certificate for
authentication and digital signature [
32
]. An eID system
provides a means for distinguishing between different cit-
izens and businesses uniquely in order to access electronic
services. eID cards are offered by migration boards and
national identity register in most countries. The same eID
can be used in multiple sectors (e.g. taxation, social secu-
rity, education, telephony services, banking services) while
fulfilling different roles (e.g. a civil servant or a business-
man) depending on the context. The existing eID man-
agement systems are not interoperable and lacks security as
a result of having single centralized system for keeping
records [
32
].
Another technical solution for security and privacy
issues in e-government is an authentication framework
proposed in [
33
]. This framework utilises different regis-
tration and authentication procedures based on a single
central citizen portal interfaced with ministerial depart-
ments. The framework consists of two parts namely Iden-
tity Provider (IdP) and the Service Provider (SP). Users
have to register with IdP at a central portal of an e-gov-
ernment system to obtain unique identities that will be used
to access services from the service providers. Whenever a
user wants to access a service, SP must authenticate his/her
identity with the IdP at the central portal to obtain a Single
Sign On (SSO) password that can be used to access dif-
ferent SPs.
3 Blockchain-based E-government system
The proposed blockchain-based e-government framework
is illustrated in Fig.
4
. In this figure, a double direction
arrow G2G shows an interaction taking place between
government departments and organizations, allowing a
Fig. 4 The proposed blockchain-based e-government network
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Wireless Networks (2023) 29:1005–1015
123
peer to peer (p2p) exchange (broadcast) and validation of
data being submitted by individuals. A G2C double
direction arrow represents information sharing between
citizens and the government such as filling forms for tax,
marriage certificates, business permits, birth certificates,
visa or passport. A G2B double direction arrow expresses
information exchange such as electronic procurement, tax
and insurance clearance forms and electronic auctions
between public and business organizations (enterprises) as
the main source of economic growth.
The joining of any new e-government (G) node or user
node (C or B) to the blockchain network is reviewed by
peers in the network, and e-government tokens are assigned
for setting up its network node, leading to a permissioned
(private) blockchain. The number of e-government tokens
is equivalent to the total number of records stored by a
node in the blockchain network. Each user has a dedicated
e-government blockchain wallet to collect his/her tokens.
Once a record is submitted, the record will be transferred in
terms of stake to his/her blockchain address. Using a DPoS
protocol, any node will be able to register with the network
as a delegate as described in Sect.
3.2
. In order to add a
new block to the blockchain, the departments that jointly
make up the e-government system vote for a delegate who
will validate the transactions and seal the block. This
approach is appropriate for security requirement, since
random nodes cannot join the network, generate new
tokens and set up a network node unless the rest e-gov-
ernment nodes approve it. The permissioned blockchain
system ensures that the stored records are trustworthy,
auditable and transparent.
3.1 Network nodes
There are two types of nodes in blockchain terminology,
which are full nodes and lightweight nodes [
18
]. A full
node downloads a full copy of the blockchain when it joins
the blockchain network, which allows it to fully validate
transactions and blocks. A lightweight node does not
download a complete copy of the blockchain when it joins
the network, but it downloads only the block headers to
validate the authenticity of transactions. To be able to
transfer their transactions to the network and receive
notifications when transactions affect their blockchain
wallets, lightweight nodes usually refer to a copy of a
trusted full node of the blockchain.
In the proposed system, e-government department nodes
serve as full nodes while user’s devices (C and B) serve as
lightweight nodes, although any business node is allowed
to download a complete copy of the blockchain. The p2p
network connectivity in the proposed network can be
provided by using wireless broadband, thanks to the fact
that many countries across the world are trying to
incorporate a city-wide wireless broadband network across
the city using the Wi-Fi technology [
34
].
3.2 Delegates and witnesses voting
Peers need to agree on a state of the block’s transactions
and the process of sealing the blocks into the blockchain, in
order for the network to remain functional. The DPoS is
adopted here as the consensus algorithm due to its com-
putational efficiency in adding transactions and sealing a
block [
19
]. Briefly, the DPoS can be viewed as a repre-
sentative democracy where the e-government nodes utilize
their stake (records) in order to elect delegates (other
nodes) to join the network. Delegates are responsible for
securing the network and voting for witnesses among them
who will validate transactions and seal the blocks.
To elect the witnesses, votes are weighed according to
the size of the tokens of each delegate or voting node. A
delegate does not need to have a large token to get selected
as a witness, but votes from delegates with large tokens can
result in delegates with relatively small tokens being
elected as witnesses. E-government nodes will store its
individual’s records, allowing them to have higher tokens
to participate and vote for witnesses which increases the
security of the proposed system. In DPoS, nodes are
allowed to delegate their voting power to other nodes,
whom they trust to vote for witnesses on their behalf. Any
delegate which appears to misbehave will be removed from
the set of participating delegates and its votes is assigned to
a new node joining the network or any existing node in
order to ensure security and trust within the network.
The choice of the underlying blockchain technology for
the prototype implementation mainly relies on the avail-
ability and efficiency of the DPoS implementation. In the
meantime, the computational energy required for validat-
ing transactions must be affordable while the security of
the established network must be guaranteed. For instance,
Ethereum platform implements DPoS and smart contract
protocol to simulate real contracts such as tax and insur-
ance contracts, employment contracts, and land registry
[
35
]. It provides an important alternative in e-government
to store citizens’ sensitive records, due to its ability to
facilitate contract negotiation, simplify contract terms,
implement contract execution, and verify contract fulfill-
ment state.
3.3 New node creation
The process of registering a new node to the proposed
e-government network is summarised in ‘‘Algorithm 1’’.
Any e-government department can join the blockchain net-
work by setting up a full network node while other users can
only set up lightweight nodes. Once a new node join the
Wireless Networks (2023) 29:1005–1015
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123
network, a functional node will generate its blockchain
wallet and address containing public and private keys as
shown in lines 7 and 8 in ‘‘Algorithm 1’’. The private key is
used by each node to sign and validate transactions therefore
it must be kept safely (line 9). After generating the address, a
node will contact delegates in the blockchain network to send
its registration request, and one of the delegates will verify its
registration and transfer some e-government tokens (regis-
tration record) in its blockchain address.
Thereafter, a new node is added to the network, and its
registration is broadcasted to the network peers by the
assigned delegate (line 12–14), allowing other network peers
to receive its wallet information for sending transactions in
the next cycle. Additionally, a new node receives instruc-
tions for a network node setup so that it can be elected as a
delegate to validate transactions in the next cycle. Subse-
quently, the new node sets up the network node according to
the instruction provided. In particular, the instruction con-
sists of the size of initial token, the blockchain address of a
node, and the public and private keys for signing and vali-
dating transactions before adding a block.
The process of adding a new node is completed when a
network node is successfully set up and broadcasted to the
network by a delegate. Information security is enhanced by
using encrypted data distributed across the network.
Therefore, even if a malicious node is registered as a
department node, it cannot alter the data as every partici-
pating peer in the network is able to detect the alteration
and invalidate the change.
3.4 User registration
Users make their registrations using their network devices
or physically visiting one of the government departments,
with the process summarised in ‘‘Algorithm 2’’. As
described in lines 2 and 3 in this algorithm, an ID for a user
is issued and a new blockchain address is generated for the
user containing public and private keys, allowing the
identification of the owner. A Blockchain wallet for this
new user is created and broadcasted (lines 5–8) so that each
node can store it in its blockchain address. The created
blockchain wallet is then used to send and receive trans-
actions related to the user’s account. User IDs and private
keys will be stored safely in the wallet file or the database
of the user’s device. Users can conveniently view their
records and the new transaction available in their block-
chain addresses through the wallet interface.
When a user submits a record to a delegate, the trans-
action is authenticated and initialized. From this, the block
is updated to a new version which is broadcasted across the
network for validation and then transferred to his/her
blockchain address in all network peers. The transferred
record is stored in the blockchain address of the user with
the following data content: (1) the ID of the user, (2) the
record value such as property registration, and (3) the
record identification such as tax registration number. Each
data instance in a blockchain represents an asset.
When a third party organization (e.g., business) requests
to access a user’s information for any official issues, the
user needs to provide his/her blockchain address for veri-
fication. The organisation can then use the blockchain web
API to access the blockchain data stored in the user’s
address. All e-government users are required to backup
their private keys and keep them safe. If any user lost his/
her private key, (s)he will be required to create a new
blockchain address and request one of the e-government
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Wireless Networks (2023) 29:1005–1015
123
department node to transfer his/her information from the
old blockchain address to a newly created blockchain
address.
The user’s device and identity will be validated and
authenticated, when a registered user wants to access the
network. This helps to minimise human errors which have
always been considered as a main contribution of failure
and a weak link to access information stored in information
systems [
36
]. As a result, government information will flow
securely and seemingly to the right individuals at the right
time and right place. Typical human errors in cyber secu-
rity include sending sensitive data to the wrong recipient
and unintentionally exposing login credentials such as
username and passwords. According to [
37
], human error
remain as one of the main causes for cyber security breach
in the public and private organisations.
3.5 New block generation
Every block is created by one active witness who is
selected at random by the majority of peers from the list of
active delegates. If a witness misses a block, another wit-
ness is tasked to create and validate the block to join the
blockchain network. In DPoS, a fixed period of time is set
for block creation, often five seconds [
19
]. ‘‘Algorithm 3’’
highlights the fundamental steps involved in the process of
generating and adding a block to the blockchain using the
DPoS consensus algorithm.
A block is added in a regular interval of time, T
c
. Within
this interval, the block undergoes the following phases of
activities. First, an empty set of transactions R is initial-
ized; and one witness from a group of delegates is elected
to create and validate the transactions for the blockchain.
Secondly, all the transactions are sent to the elected wit-
ness. This process continues until the witness stops
accepting any new transactions for the block. Thirdly, the
witness assembles the new block and distributes it to the
network delegates for review and verification. This allows
those nodes that elected the witness to digitally sign the
block to prove its correctness. The signed block is returned
to the witness and added to its local blockchain while
simultaneously distributing the new block to the network.
The witness cannot mine its own transaction and hence in
lines 4 and 9, b (witness) is excluded from the set of nodes
N. At the end of the algorithm, the blockchain is distributed
to all government nodes in the network.
4 Security and privacy analysis
Every e-government system must guarantee the confiden-
tiality, integrity and availability of the services. Confi-
dentiality is achieved when information is not disclosed to
unauthorised users; integrity is achieved by protecting
information from any form of modification, whilst avail-
ability means information is available when needed and is
free from DoS or DDoS or other similar service disruption.
This section provides a theoretical qualitative analysis on
the security and privacy performance of the blockchain-
based e-government system.
The records stored in the proposed system are secured
through the public key cryptography that protects against
adversarial attempts to alteration and/or unauthorised
access, whilst network users are assigned with private keys
for validating and signing transactions. Encryption and
digital signature are used in the network to ensure security,
privacy and access control to the stored records. Moreover,
most of the blockchain consensus algorithms (in this case
DPoS) require an attacker to control at least 51% of the
network peers in order to alter a record [
20
], which is
generally impossible to achieve. More precisely, in order to
change any block in the blockchain, an attacker has to
modify every copy of that block in the network and then
convince most of the nodes that the new block is the valid
one. Also, to increase the privacy of the data stored in the
proposed network, all user’s blocks are hashed and an
incomprehensible hashes of the transactions are stored in
the blockchain.
The proposed system is a decentralized p2p system
where the user’s data are stored in different nodes which
Wireless Networks (2023) 29:1005–1015
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123
guarantees the availability of the system by avoiding any
single point of failure. Using DPoS, it is difficult for any
adversary to launch DDoS or DoS attacks against the
system as registration is required for a node to start sharing
information with the rest of the network peers. Any
transactions received from the network node are validated
by the witnesses making it difficult for malicious nodes to
initiate malicious connections.
The security services and corresponding common mea-
sures provided by the proposed framework is summarised
in Table
1
, which ensure adequate privacy and security of
the transactions. For computational efficiency, user’s
devices will run lightweight client to store the transactions
rather than the complete copy of the blockchain which is
expensive in terms of storage. E-government devices are
expected to be computationally powerful with enough
storage capacity to store and process user’s records effi-
ciently. The network is able to offer the performances
provided by the blockchain technology and DPoS con-
sensus protocol such as scalability, speed, interoperability,
and transparency, and it can handle a large number of
transactions.
The elliptic curve cryptography (ECC) approach is
adopted for implementing encryption and digital signature
in the proposed framework, which is a common practice for
most of the existing blockchain technologies such as Bit-
coin and Ethereum. Note that the ECC and the RSA
(Rivest-Shamir-Adleman) offers a similar level of security
but ECC consumes far less number of bits [
38
]. For
instance, a 256-bit key in ECC offers the same level of
security as that provided by the RSA using a 3072-bit key.
Shorter key usually means low CPU consumption, low
memory usage and fast key generation. These advantages
are also beneficial to the proposed framework in facilitating
fast creation of the transactions and sealing the blocks. A
summary of key length study between the RSA and ECC is
provided in Table
2
[
38
]. 256-bit ECC keys are widely in
Table 1 Security services and common measures
Security service
Countermeasure (s)
Authentication
Blockchain address and digital signature
Access control
Digital Signature and encryption
Confidentiality
Encryption
Integrity
Encryption and digital signature
Non-repudiation
Encryption and digital signature
Availability
Distributed/decentralised
Trust
Decentralized, encryption and digital signature
Table 2 Comparison between RSA and ECC key lengths in bits
RSA key length
ECC key length
Approx. ratio (RSA:ECC)
1024
160
6:1
2048
224
9:1
3072
256
12:1
7680
348
20:1
15360
512
30:1
Table 3 Features of blockchain-based e-government system
Feature
Justification
Reduced human errors
User devices and identities are authenticated in advance before gaining access to the network
Increased public trust
Individuals have direct control of their information and all network participants are authenticated
Greater scalability
The system can easily scale up as it allows new devices and users to be added to the network automatically following
the consensus mechanism
Improved reliability
Data are stored in multiple servers/locations. The consensus protocol ensures that data can only be altered when all
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