Campbellsville University Critical Challenges to Blockchain Technology Paper Please Read the question and attached PPTS instructions thoroughly and then st
Campbellsville University Critical Challenges to Blockchain Technology Paper Please Read the question and attached PPTS instructions thoroughly and then start work on my question and make sure no Plagiarism
History has shown that innovations in various technologies spread at such a rapid pace among consumers and communities that the latter hardly paid a more serious attention to existing flaws and limitations of these innovations. Quite similar is the case with blockchain technology. Only through trial and error as well as through research and development experts in the field were able to understand its current issues and limitations.
The main limitation to Blockchain technology is its complexity. As you will see in this week’s lecture and PowerPoint, there are other limitations as well. Please be sure to review the readings for the week to get a better understanding of the limitations and challenges. We are close to finishing the term, so please be sure to review any past readings on blockchain to ensure you have a deep and solid understanding of blockchain.
The Final Portfolio Project is a comprehensive assessment of what you have learned during this course.
The Final Project has two parts: Limitations of Blockchain and Emerging Concepts.
Blockchain continues to be deployed into various businesses and industries. However, Blockchain is not without its problems. Several challenges have already been associated with the use of this technology. Identify at least 5 key challenges to Blockchain. Additionally, discuss potential solutions to these challenges. Lastly, please discuss if we will see the limitations to blockchain be reduced or mitigated in the future.
There are several emerging concepts that are using Big Data and Blockchain Technology. Please search the internet and highlight 5 emerging concepts that are exploring the use of Blockchain and Big Data and how they are being used.
Conclude your paper with a detailed conclusion section which discusses both limitations and emerging concepts.
The paper needs to be approximately 8 pages long, including both a title page and a references page (for a total of 10 pages). Be sure to use proper APA formatting and citations to avoid plagiarism.
Your paper should meet the following requirements:
• Be approximately 8 pages in length, not including the required cover page and reference page.
• Follow APA7 guidelines. Your paper should include an introduction, a body with fully developed content, and a conclusion.
• Support your answers with the readings from the course, the course textbook, and at least four scholarly journal articles from the UC library to support your positions, claims, and observations, in addition to your textbook. The UC Library is a great place to find resources.
• Be clearly and well-written, concise, and logical, using excellent grammar and style techniques. You are being graded in part on the quality of your writing. Blockchain Challenges and Security Schemes:
A Survey
Sirine SAYADI
MEDIATRON Laboratory
Higher School of
Communication of Tunis,
Sonia BEN REJEB
MEDIATRON Laboratory
Higher School of
Communication of Tunis,
Sirine.sayadi@supcom.tn
sonia.benrejeb@supcom.tn
Ziéd CHOUKAIR
MEDIATRON Laboratory
Higher School of
Communication of Tunis,
Z.choukair@supcom.tn
Abstract With the increasing number of connected devices
and the number of online transactions today, managing all
these transactions and devices and maintaining network
security is a research issue. Current solutions are mainly based
on cloud computing infrastructures, which require servers
high-end and broadband networks to provide data storage and
computing services. These solutions have a number of
significant disadvantages, such as high maintenance costs of
centralized servers, critical weakness of Internet Of Things
applications, security and trust issues, etc. The blockchain is
seen as a promising technique for addressing the mentioned
security issues and design new decentralization frameworks.
However, this new technology has a great potential in the most
diverse technological fields. In this paper, we focus on
presenting an overview of blockchain technology, highlighting
its advantages, limitations and areas of application.
Since its inception, from the initial cryptocurrency to the
current smart contract, blockchain technology has shown
promising prospects in many areas of application.
The originality of this work resides in the comparison
between the different blockchain systems and their security
schemes and the perspective of integrating this technology into
secured systems models for our comfort and our private life.
This section presents a complete visualization of
blockchain technology, how it works, its structure and
existing types.
Keywords Blockchain,
Contracts, Consensus
Security,
Technology,
Smart
I. INTRODUCTION
The current network model connects multiple computing
devices and will continue to support small-scale Internet of
Things networks that will not be able to meet the growing
needs of tomorrow’s large ecosystems. Centralized cloud
servers will remain a bottleneck. throttling and a point of
failure that can disrupt the network.
In this context, Blockchain technology appeared in 2009
by Nakamoto [1] “Bitcoin Developers” as a storage
technology serving decentralized large registers and as a
security technique for authenticating, authorizing and
verifying data generated.
With blockchain technology the concept of consensus has
emerged as a mechanism that ensures trust in communication
between two entities without the intervention of an
intermediary. We can use blockchain in cryptocurrency,
smart contracts, digital identity management, internet of
things, access control applications, automated peer-to-peer
insurance, in banks and in many other applications [2].
978-1-5386-5651-8/18/$31.00 ©2018 IEEE
This proposed paper will be a state-of-the-art study on
blockchain technology. Section 2 will present an overview of
blockchain technology. Section 3 will describe a semantic
study of the potential of blockchain technology. We present
in Section 4 some cases of use of this technology. Then we
will examine the security threats, some real attacks for this
technology, and its security enhancement solutions in Section
5 and finally we will conclude our paper by suggesting future
directions.
II. OVERVIEW OF BLOCKCHAIN TECHNOLOGIES
A. Blockchain Process
The Blockchain process is described as a transaction
between users on the network that are grouped into blocks.
The block is validated and saved on the network by a
«minor » according to cryptographic techniques that depend
on the rules of the type of blockchain used.
In the bitcoin blockchain this technique is called the
“Proof-of-Work”, (POW), and “proof-of-stake” (POS) in the
blockchain ethereum. If the block is validated, it is time
stamped and added to the block chain. The transaction is then
visible to the receiver as well as the entire network. This
process takes some time depending on the blockchain (about
10 minutes for bitcoin, 15 seconds for Ethereum) [8].
Each blockchain is identified by its cryptographic hash
and carries a list of transactions and a hash to the previous
block.
The exception to this is the first block in the chain, called
“genesis”, which is common to all clients in a blockchain
network and has no parent. This establishes a link between
the blocks, thus creating a chain of blocks, or blockchain.
Any node having access to this ordered and back-linked
block list can read it and understand what is the current
global state of the data exchange on the network.
C. Type of Blockchain
There are three types of Blockchain technologies
presented in the following table :
Public blockchain from which everyone can
participate in the process of reaching consensus and
verifying the transaction. Like Bitcoin [4] and Ethereum [5].
Consortium blockchains: In this type, the node
can be chosen in advance if the data in blockchain can be
public or private. They can be considered as partially
decentralized like Hyperledger [6].
Figure 1: Blockchain Process
B. Blockchain Structure
A block is composed of two main parts which are the
Block Header and the transactions (see Figure 1). The Block
header contains several fields, the most important among
them are the block version, the Merkle tree Root Hash, time
stamp, nBits, Nonce and parent block hash. Transactions are
the data saved in the block [46].
Private blockchain has strict management
authority over access to data. Nodes are restricted, not all
nodes can participate in this blockchain like Ripple [7].
Table 1: Comparative table of blockchain types [46]
These fields will be detailed below (see figure 2):
Block Version: Specifies the set of block validation
rules to follow [46].
Merkle tree Root Hash : is a condensed digital
fingerprint of all transactions in the block. The slightest
modification of a transaction in the block modifies this root.
Its principle is to calculate the hash of a node from a hash of
his sons [3].
Timestamp: current time in seconds in universal
time since January 1, 1970 [46].
nBits: target threshold of a valid block hash.
Nonce: A 4-byte field, which usually starts with 0
and increases for each hash calculation. On receipt of the new
block, the complete nodes compute the header hash only
once, to see if the Nonce is valid [37].
Parent block hash: The nodes save the data of the
block’s. Thus, all the nodes have the hash of the block 31, if
the block 32 is received by a node, it will determine that the
block 32 is the child of 31 by checking this field [37].
All types of blockchain have advantages. The choice of
blockchain type depends on our needs and our proposed
services.
III. POTENTIELS OF BLOCKCHAIN
Blockchain technology is not only a technique, but it is a
technological revolution with very important security
features, its operating model using consensus and its shared
ledger to solve the problems of traditional centralized
models.
A. Basic Security Techniques
We detail in this section the different basic security
principle by specifying how Blockchain technology can
perfectly guarantee them.
Integrity: it to ensure that the information has not
been changed, only by those authorized to make
changes. Blockchain uses cryptographic mechanisms
to guarantee that operations are immutable with the
purpose of verifying integrity.
Figure 2: Simplified Block Structure
Availability: it ensures the availability of data for
every need. the service is always active at the request
of a legitimate users. Blockchain allows users to
maintain blocks in a decentralized manner with
various copies on the blockchain.
Pivacy: is the guarantee that only authorized persons
can access to the information. The Blockchain uses a
pseudo-anonymization mechanism (hash functions) to
hide user identities to ensure confidentiality.
Authentication: a procedure by which a computer
system certifies the identity of a person or a computer
to allow that person to access certain secure resources.
The Blockchain technology provides this function by
providing private keys for users who are authorized to
carry out transactions.
Non-repudiation: Is the impossibility, for a person or
any other entity engaged in a communication, to deny
having received or sent a message, and this is ensured
by blockchain technology.
B. Shared Ledger
This is the basic feature of blockchain technology, it
means that blockchain does not have a centralized node, data
is processed, stored and updated in a decentralized way. This
avoids the problems of single deffain point and offers a peer
to peer communication such that all nodes are interconnected
and all participants in the network are equal without a central
node.
C. Smart Contract
The smart contract is autonomous computer programs
that once started, automatically execute pre-defined
conditions with conditional statements of the type « if ….
Then …. » Using the information available on the blockchain.
These contracts must be able to reduce audit costs,
execution, arbitration and fraud. They may have to manage
funds or authenticate external entities [8].
D. Consensus
A consensus is a secure fundamental trust mechanism. It
characterizes a general agreement of existence of the
members of a group. It allows you to make a decision
without the need of an intermediary or a trusted authority.
In the existing blockchain system, there are several
consensus mechanisms. We will quote the best known
below:
PoS (Proof of Stake):
A chance to validate a block is based on how much of a
stake (or cryptocurrency) the miners have. For example, if
you had 5% of the cryptocurrency, you could extract 5% of
all its transactions. People with more currency are thought to
be less likely to attack the network. Its operating principle
based on the richest person has more power in the network is
unfair because the power here depends on the balance held in
the account [46]. The PoS save more energy (reduces the
amount of calculation) but increases the flow. Unfortunately,
if the operating cost is close to zero, attacks could result.
PBFT (Practical Byzantine Fault Tolerance) :
The problem of Byzantine generals is a metaphor that
deals with questioning the reliability of transmissions and the
integrity of the interlocutors. A Byzantine fault is therefore a
failure that consists of the presentation of erroneous or
inconsistent information. The consensus “Practical Bizantine
Fault Tolerance” (PBFT) is a state machine replication
protocol that tolerates arbitrary, or “Byzantine” faults. It is
fault-resistant, fast, long-lived and an attack does not impact
its performance too much. This protocol consists of three
phases: pre-preparation, preparation & validation, it requires
3f + 1 replicates to tolerate f simultaneous Byzantine faults.
When a message is sent on the platform, the nodes retransmit
the transaction to all peers. If at least 2/3 of the nodes confirm
the validity of the transaction it is confirmed. The platform
allows users to transfer peer-to-peer ownership regardless
[46].
Many other consensus mechanisms can be found , such as
DPoS (Delegated Proof of Stake), PoB (Proof of Bandwidth)
[10], PoEt (Proof of Elapsed Time) [11], PoA (Proof of
Authority) [12], Ripple [48], Tendermint[49] etc. that are
used in some blockchain systems.
A comparison between some of the most used consensus
algorithms is presented in table 2 [46].
With these advantages presented in this section from the
basic security techniques, smart contracts, shared ledger and
the consesus, blockchain technology has attracted attention in
several areas..
In the next section, we will introduce some areas of use of
blockchain technology as a solution concept.
Table 2: Comparison between some consensus algorithms
Property
POW
POS
PBFT
Identity
management
of nodes
Without
permission
Without
permission
With
permission
partial
yes
PoW (Proof of Work) :
Method used to validate Blockchain network blocks. This
method requires users to use their computing power to
validate a block. Minors compete against each other. As a
result, the higher the computational power (combining
several computers, to increase computing power), the more
likely they are to find the result of a “Hash” function and thus
validate the block. In the Bitcoin blockchain it is necessary to
count a validation every 10 minutes approximately [9].
Energy saving
No
Power
tolerated
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