{"id":637,"date":"2022-01-26T07:19:10","date_gmt":"2022-01-26T07:19:10","guid":{"rendered":"https:\/\/sampleassignmenthelp.com\/?page_id=637"},"modified":"2022-01-26T07:19:35","modified_gmt":"2022-01-26T07:19:35","slug":"blockchain-security-issues-and-challenges-article-summary-sample","status":"publish","type":"page","link":"https:\/\/sampleassignmenthelp.com\/blockchain-security-issues-and-challenges-article-summary-sample\/","title":{"rendered":"Blockchain Security Issues and Challenges-Article Summary Sample"},"content":{"rendered":"

QUESTION<\/strong><\/p>\n

 <\/p>\n

Article<\/p>\n

A Survey of Blockchain Security Issues and
\nChallenges<\/p>\n

Abstract<\/p>\n

Blockchain technologies is one of the most popular issue in recent years, it has already changed people\u2019s lifestyle in
\nsome area due to its great influence on many business or industry, and what it can do will still continue causeim\u0002pact in many places. Although the feature of blockchain technologies may bring us more reliable and convenient services, the security issues and challenges behind this in\u0002novative technique is also an important topic that we need to concern. Keywords: Blockchain; Smart Contracts; Security<\/p>\n

1 Introduction<\/p>\n

Bitcoin is the first application of blockchain, it\u2019s a kind of
\ndigital currency based on blockchain technologies, using
\nfor trade things on the internet like money as we do in
\nthe real world. Because the success of Bitcoin, people now
\ncan utilize blockchain technologies in many field and ser\u0002vice, such as financial market, IOT, supply chain, voting,
\nmedical treatment and storage.
\nBut as we use these tools or services in our daily life,
\ncybercriminals also get opportunity to engage in cyber\u0002crime [16, 18]. For example, 51% attacks is a classic se\u0002curity issue in Bitcoin that hacker try to take control the
\nsystem\u2019s mechanism, using the same technology base.
\nIn this paper, we will have a quick study about what
\nis blockchain in Section 2, then we\u2019ll discuss different ap\u0002plication in blockchain and what service do they offer in
\nSection 3, at the end, we shall talk about the security
\nissues and those challenges we need to overcome in Sec\u0002tion 4. The paper is concluded in Section 5.<\/p>\n

2 The Concept of Blockchain<\/p>\n

Blockchain technologies is not just only single one tech\u0002nique, but contains Cryptography, mathematics, Algo\u0002rithm and economic model, combining peer-to-peer net\u0002works and using distributed consensus algorithm to solve traditional distributed database synchronize problem, it\u2019s an integrated multi- field infrastructure construction
\nThe blockchain technologies composed of six key ele\u0002ments. Decentralized. The basic feature of blockchain, means
\nthat blockchain doesn\u2019t have to rely on centralized node anymore, the data can be record, store and up\u0002date distributedly. Transparent. The data\u2019s record by blockchain system is transparent to each node, it also transparent on up\u0002date the data, that is why blockchain can be trusted. Open Source. Most blockchain system is open to every\u0002one, record can be check publicly and people can also use blockchain technologies to create any application
\nthey want. Autonomy. Because of the base of consensus, every node on the blockchain system can transfer or update data safely, the idea is to trust form single person to the whole system, and no one can intervene it. Immutable. Any records will be reserved forever, and can\u2019t be changed unless someone can take control more than 51% node in the same time.Anonymity. Blockchain technologies solved the trust problem between node to node, so data transfer or even transaction can be anonymous, only need to know the person\u2019s blockchain address.
\n\"\"
\nFigure 1: The structure of block chain<\/p>\n

2.1 How Blockchain Works?
\nThe main working processes of blockchain are as follows:
\n1) The sending node records new data and broad casting to network.
\n2) The receiving node checked the message from those data which it received, if the message was correct then it will be stored to a block.
\n3) All receiving node in the network execute proof of work (PoW) or proof of stake (PoS) algorithm to the block.
\n4) The block will be stored into the chain after execut\u0002ing consensus algorithm, every node in the network admit this block and will continuously extend the
\nchain base on this block.<\/p>\n

2.2 The Structure of Blockchain
\nGenerally in the block, it contains main data, hash of pre\u0002vious block, hash of current block, timestamp and other
\ninformation. Figure 1 shows the structure of block. Main data. Depending on what service is this blockchain applicate, for example: transaction records, bank clearing records, contract records or IOT data record. Hash. When a transaction executed, it had been hash to a code and then broadcast to each node. Be\u0002cause it could be contained thousands of transaction records in each node\u2019s block, blockchain used Merkle tree function to generate a final hash value, which is also Merkle tree root. This final hash value will be record in block header (hash of current block), by using Merkle tree function, data transmission and computing resources can be drastically reduced.Timestamp. Time of block generated. Other Information. Like signature of the block, Noncevalue, or other data that user define.<\/p>\n

2.3 How to Get Consensus
\nConsensus function is a mechanism that make all blockchain nodes have agreement in same message, can make sure the latest block have been added to the chain correctly, guarantee the message that stored by node was the same one and won\u2019t happened \u201cfork attack\u201d, even can protect from malicious attacks.<\/p>\n

2.4 Proof of Work (PoW)
\nA proof of work is a piece of data which is difficult (costl or time-consuming) to produce but easy for others to ver\u0002ify and which satisfies certain requirements. Producing a proof of work can be a random process with low probabil\u0002ity so that a lot of trial and error is required on average before a valid proof of work is generated. Bitcoin uses the Hashcash proof of work system. When calculating PoW, it\u2019s called \u201cmining\u201d. Each block has a random value called \u201cNonce\u201d in block header, by changing this nonce value, PoW have to generate a value that makes this block header hash value less than a \u201cDifficulty Target\u201d which has already been set up. Dif\u0002ficulty means how much time it will take when the node calculating hash value less than target value. In order for a block to be accepted by network partici\u0002pants, miners must complete a proof of work which covers all of the data in the block. The difficulty of this work is adjusted so as to limit the rate at which new blocks can be generated by the network to one every 10 minutes.
\nDue to the very low probability of successful generation, this makes it unpredictable which worker computer in the
\nnetwork will be able to generate the next block<\/p>\n

2.5 Proof of Stake (PoS)
\nBecause Proof of Work method will cause a lot of electric\u0002ity power and computing power be wasted, Proof of Stake
\ndoesn\u2019t need expensive computing power. With Proof of Stake, the resource that\u2019s compared is the amount of Bit\u0002coin a miner holds – someone holding 1% of the Bitcoin can mine 1% of the \u201cProof of Stake blocks\u201d [12].
\nA Proof of Stake method might provide increased pro\u0002tection from a malicious attack on the network. Addi\u0002tional protection comes from two sources: International Journal of Network Security<\/p>\n

\"\"
\nFigure 2: Public blockchain<\/p>\n

\"\"
\nFigure 3: Consortium blockchain<\/p>\n

1) Executing an attack would be much more expensive.
\n2) Reduced incentives for attack. The attacker would need to own a near majority of all bitcoin. Therefore, the attacker suffer severely from his own attack.<\/p>\n

2.6 Type of Blockchain
\nBlockchain technologies can be roughly divided into three types.
\n1) Public blockchain: Everyone can check the trans\u0002action and verify it, and can also participate the pro\u0002cess of getting consensus. Like Bitcoin and Ethereum are both Public Blockchain. Figure 2 shows public blockchain.
\n2) Consortium blockchains: It means the node that had authority can be choose in advance, usually has partnerships like business tobusiness, the data in blockchain can be open or private, can be seen as Partly Decentralized. Like Hyperledger and R3CEV are both consortium blockchains. Figure 3 shows consortium blockchains.
\n3) Private blockchain: Node will be restricted, not every node can participate this blockchain, has strict authority management on data access. Figure 4shows private blockchain. No matter what types of blockchain is, it both has
\nadvantage. Sometimes we need public blockchain be\u0002cause its convenience, but sometimes we maybe need private control like consortium blockchains or private blockchain, depending on what service we offer or
\nwhat place we use it.<\/p>\n

\"\"
\nFigure 4: Private blockchain<\/p>\n

3 Application of Blockchain Tech\u0002nologies Blockchain technologies can be using in many area, not only in financial application, but also in others industries.<\/p>\n

3.1 Digital Currency: Bitcoin Bitcoin\u2019s data structure and transaction system was built by blockchain technologies, makes Bitcoin became a digi\u0002tal currency and online payment system. By using en\u0002crypted technique, funds transfer can be achieved and
\ndoesn\u2019t need to rely on central bank. Bitcoin used public keys address sending and receiving bitcoin, recorded the
\ntransaction and the personal ID was anonymous. The process of transaction confirm needs other user\u2019s comput\u0002ing power to get consensus, and then records the transac\u0002tion to network.<\/p>\n

3.2 Smart Contract: EthereumSmart Contract is a digital contract that controls user\u2019s
\ndigital assets, formulating the participant\u2019s right and obli\u0002gation, will automatically execute by computer system.
\nIt\u2019s not only just a computer procedure, it can be seen
\nas one of a contract participants, will response to mes\u0002sage what it receive and store the data, it can also send
\nmessage or value to outside. Smart Contract is just like a
\nperson can be trusted, can hold the assets temporarily and
\nwill follow the order which has already been program [13].
\nEthereum is an open source blockchain platform com\u0002bining Smart Contract, offering decentralized virtual ma\u0002chine to handle the contract, by using its digital currency
\ncalled ETH, people can create many different services,
\napplications or contracts on this platform .<\/p>\n

3.3 HyperledgerHyperledger is an open source blockchain platform, started in December 2015 by the Linux Foundation, to support blockchain-based distributed ledgers. It is fo\u0002cused on ledgers designed to support global business transactions, including major technological, financial, and supply chain companies, with the goal of improving many
\naspects of performance and reliability. The project aims International Journal of Network Security,
\nto bring together a number of independent efforts to de\u0002velop open protocols and standards, by providing a modu\u0002lar framework that supports different components for dif\u0002ferent uses. This would include a variety of blockchains with their own consensus and storage models, and services for identity, access control, and contracts.<\/p>\n

3.4 Other ApplicationsThere still have many use case of blockchain technologies, like protection of Intellectual property, traceability in sup\u0002ply chain, identity certification, insurance, internationalpayments, IOT, patient\u2019s privacy in medical treatment or prediction market .<\/p>\n

4 Security Issues and ChallengesSo far, blockchain has been gotten many attention in dif\u0002ferent area, however, it also exists some problems and
\nchallenges needs to face it .<\/p>\n

4.1 The Majority Attack (51% Attacks)With Proof of Work, the probability of mining a block depends on the work done by the miner (e.g. CPU\/GPU
\ncycles spent checking hashes). Because of this mechanism,people will want to join together in order to mining more
\nblocks, and become \u201cmining pools\u201d, a place where hold\u0002ing most computing power. Once it hold 51% computing
\npower, it can take control this blockchain. Apparently, it cause security issues [3, 4]. If someone has more than 51% computing power, then he\/she can find Nonce value quicker than others, means he\/she has authority to decide which block is permissible.
\nWhat it can do is:
\n1) Modify the transaction data, it may cause double\u0002spending attack [11, 17].
\n2) To stop the block verifying transaction.
\n3) To stop miner mining any available block.
\nA majority attack was more feasible in the past whenmost transactions were worth significantly more than the
\nblock reward and when the network hash rate was muchlower and prone to reorganization with the advent of new
\nmining technologies .<\/p>\n

\n4.2  Fork ProblemsAnother issue is fork problem. Fork problem is related to decentralized node version, agreement when the software
\nupgrade. It is a very important issue because it involving a wide range in blockchain.
\n\u2022 Types of Forks
\nWhen the new version of blockchain software pub\u0002lished, new agreement in consensus rule also changed<\/p>\n

\"\"
\nFigure 5:Hard Fork to the nodes.<\/p>\n

Therefore, the nodes in blockchain net\u0002work can be divided into two types, the New Nodes
\nand the Old Nodes. So here come four situations:
\n1) The new nodes agree with the transaction ofblock which is sending by the old nodes.
\n2) The new nodes don\u2019t agree with the transactionof block which is sending by the old nodes.
\n3) The old nodes agree with the transaction ofblock which is sending by the new nodes.
\n4) The old nodes don\u2019t agree with the transactionof block which is sending by the new nodes.Because of these four different cases in getting con\u0002sensus, fork problem happens, and according to these four cases, fork problems can be divided into two types, the Hard Fork and the Soft Fork. In addi\u0002tion to distinguish the new nodes and the old nodes, we have to compare the computing power of new nodes with old nodes, and assume that the comput\u0002ing power of new nodes are more than 50<\/p>\n

\n\u2022 Hard Fork
\nHard Fork means when system comes to a new ver\u0002sion or new agreement, and it didn\u2019t compatible with previous version, the old nodes couldn\u2019t agree with the mining of new nodes, so one chain became two chains. Although new nodes computing power were stronger than old nodes, old nodes will still continue to maintain the chain which it though was right. Fig\u0002ure 5 shows the hard fork problem. When Hard Fork happens, we have to request all nodes in the network to upgrade the agreement, theInternational Journal of Network Security<\/p>\n

\"\"
\nFigure 6: Hard Fork happens because the old node veri\u0002fication requirement is much stricter than the new node<\/p>\n

\"\"
\nFigure 7: Compatible hard fork<\/p>\n

\nnodes which haven\u2019t been upgrade will not continue to work as usual. If there were more old nodes didn\u2019t upgrade, then they will continue to work on the other completely different chain, which means the ordinary chain will fork into two chains. Figure 6 shows the reason of why hard fork will happens.<\/p>\n

\n\u2022 Soft Fork
\nSoft Fork means when system comes to a new version or new agreement, and it didn\u2019t compatible with pre\u0002vious version, the new nodes couldn\u2019t agree with the mining of old nodes. Because the computing power of new nodes are stronger than old nodes, the block which is mining by the old nodes will never be ap\u0002prove by the new nodes, but new nodes and old nodes will still continue to work on the same chain.<\/p>\n

Figure 7 shows the soft fork problem.
\nFigure 8: Soft Fork happens because the new node verifi\u0002cation requirement is much stricter than the old node<\/p>\n

\nWhen Soft Fork happens, nodes in the network don\u2019t have to upgrade the new agreement at the same time, it allows to upgrade gradually. Not like Hard Fork, Soft Fork will only have one chain, it won\u2019t affect the stability and effectiveness of system when nodes upgrade. However, Soft Fork makes the old nodes unaware that the consensus rule is changed, contrary to the principle of every nodes can verify correctly tosome extent.<\/p>\n

\"\"<\/p>\n

Figure 8 shows the reason of why softfork will happens.<\/p>\n

\n4.3 Scale of BlockchainAs blockchain growing, data becomes bigger and bigger, the loading of store and computing will also getting harder and harder, it takes plenty of time to synchronize data, in the same time, data still continuely increase, brings a big problem to client when running the system [10]. Simplified Payment Verification (SPV) is a
\npayment verification technology, without maintain full blockchain information, only have to use block header
\nmessage. This technology can greatly reduce user\u2019s stor\u0002age in blockchain payment verification, lower the user\u2019s
\npressure when transaction drastically increased in the fu\u0002ture.<\/p>\n

\n4.4 Time Confirmation of Blockchain Data
\nCompared to traditional online credit card transaction,usually takes 2 or 3 days to confirm the transaction, bit\u0002coin transaction only have to use about 1 hour to verify, it\u2019s much better than the usual, but it\u2019s still not good enough to what we want it to. Lightning Network is a solution to solve this problem .
\nLightning Network is a proposed implementation of Hashed Timelock Contracts (HTLCs) with bi-directional
\npayment channels which allows payments to be securely routed across multiple peer-to-peer payment channels.
\nThis allows the formation of a network where any peer International Journal of Network Security.on the network can pay any other peer even if they don\u2019t directly have a channel open between each other.<\/p>\n

\n4.5 Current Regulations Problems
\nUse Biction for example, the characteristics of decentral\u0002ized system, will weak the central bank\u2019s ability to con\u0002trol the economic policy and the amount of money, that makes government be cautious of blockchain technologies, authorities have to research this new issue, accelerate for\u0002mulating new policy, otherwise it will have risk on the market.<\/p>\n

\n4.6 Integrated Cost Problem
\nOf course it will have lot of cost including time and money to change existing system, especially when it\u2019s an infras\u0002tructure. We have to make sure this innovative technology not only create economic benefits, meet the requirements of supervision, but also bridge with traditional organi\u0002zation, and it always encounter difficulties from internal organization which is existing now.<\/p>\n

\n5 Conclusions
\nThere\u2019s no doubt that blockchain is a hot issue in recent years, although it has some topics we need to notice, some
\nproblems has already been improved along with new tech\u0002nique\u2019s developing on application side, getting more and
\nmore mature and stable.The government have to make corresponding laws for this technology, and enterprise should ready for embrace blockchain technologies, preventing it brings too much im\u0002pact to current system.
\nWhen we enjoy in the advantage of blockchain tech\u0002nologies bring to us, in the same time, we still have to
\nstay cautious on its influence and security issues that it could be have.<\/p>\n

\nAcknowledgments
\nThis study was supported by the National Science Council
\nof Taiwan under grant NSC 105-2410-H-005 -023 -MY2.
\nThe authors gratefully acknowledge the anonymous re\u0002viewers for their valuable comments.<\/p>\n

ANSWER<\/strong><\/p>\n

SUMMARY<\/p>\n

This article tries to bring in a small glimpse of a new technology named block chain that is recently revolutionizing the world. It brings to us after a short introduction of what it is, the characteristics that it has and that makes It separate from all others like transparent, immutable, open source etc. It also goes on to add a small description about the new technology of the Bitcoin the success of which has helped to revolutionize the world of monetary transaction and has worked as a base on which the block chain technology has expanded itself to new heights and spread far and wide. It then moves on to describe the 3 main types of block chain (Public, Private and consortium) and talks to us about some of the applications in which it is being used like ethereum, bitcoin etc. It then winds up by talking about some of the problem that this technology is facing like huge number of attacks, fork problems and the current regulations guiding it.<\/p>\n

Looking for best IT Management Assignment Help<\/a><\/span><\/span><\/span>. Whatsapp us at +16469488918 or chat with our chat representative showing on lower right corner or order from <\/span><\/span><\/span>here<\/span><\/span><\/span><\/a><\/u><\/span>. You can also take help from our <\/span><\/span><\/span>Live Assignment helper<\/span><\/span><\/span><\/a><\/u><\/span> for any exam or live assignment related assistance.<\/span><\/span><\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

QUESTION   Article A Survey of Blockchain Security Issues and Challenges Abstract Blockchain technologies is one of the most popular issue in recent years, it has already changed people\u2019s lifestyle in some area due to its great influence on many business or industry, and what it can do will still continue causeim\u0002pact in many places. […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"om_disable_all_campaigns":false,"_mi_skip_tracking":false,"footnotes":""},"class_list":["post-637","page","type-page","status-publish","hentry","post"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/sampleassignmenthelp.com\/wp-json\/wp\/v2\/pages\/637","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sampleassignmenthelp.com\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sampleassignmenthelp.com\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sampleassignmenthelp.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/sampleassignmenthelp.com\/wp-json\/wp\/v2\/comments?post=637"}],"version-history":[{"count":3,"href":"https:\/\/sampleassignmenthelp.com\/wp-json\/wp\/v2\/pages\/637\/revisions"}],"predecessor-version":[{"id":648,"href":"https:\/\/sampleassignmenthelp.com\/wp-json\/wp\/v2\/pages\/637\/revisions\/648"}],"wp:attachment":[{"href":"https:\/\/sampleassignmenthelp.com\/wp-json\/wp\/v2\/media?parent=637"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}