Blockchain technology these days is a topic that almost has its place in the discourse of most people in society, But few people know exactly what blockchain is. People’s definitions and perceptions are often not that comprehensive. This technology, which has gradually grown in the last decade and is known by more people every day, has a history of more than ten years, and the bare roots of the idea of ​​such a network can be found in the previous millennium.

In this article, we will provide a brief introduction to the definition of blockchain. Then we will examine the structure of blockchain, types of blockchain, applications of blockchain, security of blockchain, and the future of blockchain.

First, let us emphasize that digital currency is part of the blockchain. Most people consider blockchain a digital currency and use these terms interchangeably. Still, blockchain is a much bigger technology than digital currency and has found a special place in computer science. In addition, digital currency is distinct from cryptocurrency or cryptocurrency, which are often used interchangeably among the public.

What is blockchain?

The term blockchain is composed of two words Block and Chain, which can mean a chain of blocks; But to understand the concept of blockchain technology, we need to define all the pieces of the puzzle. It is good to know that the two words blockchain and chain are used separately in Satoshi Nakamoto’s original documents, and in 2016, the compound word blockchain became famous.

In general, it can be said that blockchain, in other words, is a database consisting of a list of transaction records that is constantly growing and increasing in number. These records are called blocks, which are connected through cryptography. Blocks are placed in a chain of nodes with a peer-to-peer network, and the storage tank formed is called a digital ledger. In other words, blockchain is a distributed ledger that makes the history of digital assets immutable and transparent using decentralization and cryptographic hash.

When a user creates a document and shares it with a group of people, the paper is distributed rather than copied or assigned. This process begins a decentralized distribution chain where everyone has access to the document simultaneously. A simple example of understanding blockchain is comparing it with the Google Doc service.

None of the people are blocked while waiting for changes to be made by another person, and all the changes are recorded on the document without delay, and the changes are entirely transparent. Of course, blockchain technology is much more complex than Google Docs.

The historical course of blockchain from the beginning and innovations of this technology

During the past few decades, some technologies have significantly impacted all levels of society and created a revolution in how people live. For example, the introduction of the mobile phone has revolutionized the entertainment industry and how some groups make money. Until today, new smartphones with unique capabilities are unveiled daily.

Now, we are in the middle of another technological revolution called the blockchain network, A distributed network of databases that grows and stabilizes itself every moment.

With a brief look at the last decade, we can see that the first major blockchain innovation was the birth of Bitcoin as the first cryptocurrency. The market value of Bitcoin has now reached more than 330 billion dollars and is used by millions of users daily for various payments.

The second blockchain innovation was essentially the realization that Bitcoin’s underlying technology could be separated from cryptocurrency and used to achieve other goals.

The third innovation of this technology was the birth of the “smart contract,” introduced in the second generation of the blockchain system called Ethereum. A bright future can be predicted for it.

The fourth major innovation in blockchain-based networks was various consensus mechanisms, which were initially introduced with the Proof-of-Work method and reached the Proof-of-Stake process, and continued to develop consensus methods to other proofs. Such as PoH, PoB, PoA, and PBFT resulted.

Therefore, in the beginning, most of the blockchain networks used the proof-of-work process to maintain the network’s security, based on which the group that had the most processing power to produce (mining) the blocks made the final decision and reached a consensus about the transactions and blocks.

But on the other hand, the PoS process allows people to participate in the production and validation of the block transaction according to the number of native coins of the network that are owned and placed at its disposal.

In other words, by investing in the blockchain network, people will get permission to validate, extract, and receive more rewards from the web. Of course, this method can be used when the network has reached a suitable number of participants, and the active nodes run the limit.

The fifth innovation on the blockchain technology horizon is the Scaled Blockchain. Currently, in the blockchain world, every computer on the network processes all transactions. This problem causes slow network speed. Scalable blockchain can increase processing speed without reducing security. In this method, the result is sorted faster by recognizing the number of computers needed to validate each transaction and dividing the processing work between them. Finally, with the significant increase in transaction processing speed, the blockchain network is ready to compete with payment networks such as VISA and SWIFT.

Now let’s go back in time and explore the history of blockchain. In summary, in tracing the initial steps for the emergence of blockchain, we can go before more than three decades:

• The year 1982 AD (1361 solar):

In his treatise “Computer Systems Established, Maintained, and Trusted by Mutually Suspicious Groups, David Chaum first proposed a blockchain-like protocol.”

• 1991 AD (1370 AD):

Stuart Haber and W. Scott Stornetta introduced the cryptographic blockchain.

• The year 1998 AD (1377 solar):

Computer scientist Nick Szabo studied and theorized on the Bit Gold project as a decentralized digital currency. Some people believe that the possible Satoshi Nakamoto is Mr. Sabu.

• The year 2000 AD (1379 solar):

Stefan Konst published his theory of secure crypto chains and ideas for implementation.

• 2008 AD (1387 solar year):

A developer with the pseudonym Satoshi Nakamoto published the first white paper to create a model of the blockchain network.

• The year 2009 AD (1388 solar year):

Nakamoto implemented the first blockchain network as a public distributed ledger for transactions made with Bitcoin.

• The year 2014 AD (1393 solar):

Blockchain technology was separated from digital currency, and its capabilities for other financial and inter-organizational transactions were investigated. The second version of blockchain has emerged, which includes cross-currency applications. The Ethereum blockchain system incorporated computer programs into blocks that replaced financial instruments such as bonds, known as smart contracts.

Blockchain architecture; How does blockchain work?

In general, the blockchain network consists of several layers, which include the following:

• Infrastructure (hardware, nodes)
• Networking (node ​​discovery, information replication, and validation)
• Consensus (with the help of Proof of Work PoW or Proof of Stake PoS)
• Data (blocks and transactions)
• Application layer (smart contract and decentralized applications )

To understand blockchain technology and before talking about how to implement it, we first review the essential concepts. Blockchain stores all the information in a section called the system’s ledger. In addition, in the blockchain network, any information exchanged is called a ” transaction. ” In the past, blockchain was only used for digital currency transactions; But today, different types of data can be exchanged in the platform of the blockchain-based network.

Block

Each chain consists of several blocks, and each block has three essential elements:

• The data in the league.
• A 32-bit number that we call Nonce. This number will be randomly generated when the block is created, and then it will cause the header hash of the league.
• A hash is a 256-bit number that is combined with a Nonce number. This number must start with a large number of zeros; In other words, it will be a minimal decimal number.

When the first block of the chain is created, the nonce number generates the cryptographic hash. The data inside the block is sealed and forever tied to the Nance and Hash number unless it is mined.

Miner

In the process of mining, miners create new blocks on the chain. In Lockchain, each block has a unique Nance and Hash number; But on the other hand, it also refers to the hash of the previous block in the chain; Therefore, mining a partnership is not easy, especially in large chains; it will be tough.

Miners use special software to perform complex mathematical calculations to obtain a specific nance number that produces a good blockchain hash. Since the Nance number is 32 bits and the soup is 256 bits, there are approximately 4 billion possible combinations for the Nance number and the soup that must be mined to get the correct combination. When the right combination is successful, the miner has found the “Golden Nonce,” and its new block will be added to the chain.

Making changes to any block in the chain requires re-mining all subsequent blocks. For this reason, it is tough to manipulate the blockchain network because it takes a lot of time and computing power to obtain the golden nance. Also, when a new block is mined, the changes within it are accepted by all active nodes in the network, and the miner receives a reward.

Node

One of the most important features of blockchain is decentralization. This means that no computer or organization can become the chain owner. Instead, its network consists of a distributed ledger of nodes connected to the chain. A node in a blockchain network is any electronic device that can store a copy of the blockchain and help the network function. Then, each user receives a unique identification number.

Each user on the network is known as a node, and all users have an updated version of the ledger. Each node has a different method of communicating with other nodes, which way varies from blockchain to blockchain.

Blockchain uses the Consensus Algorithm process to verify and validate requests. In the first step, a user requests a transaction on the network. Registering the proposal creates a block with all the transaction information. This block is encrypted to ensure the security of data. Then, the new block is broadcast to all active nodes in the network so that other nodes can verify the validity of the user’s request. When the created block is valid, it is placed on the chain, and the transaction requested by the user is executed.

The main layers in blockchain architecture can be classified from inner to outer in the following order.

1- Application layer

This layer includes decentralized applications ( dApps ), dApp browsers, user interfaces, and application hosting. You can access the financial fields from the browsers inside the Metamask or TrustVault application. DEPs are decentralized applications that are currently active in the area of financial services, including transactions, loans, swaps, etc. In addition, decentralized applications exist today in games such as Upland, messengers such as Session, storage platforms, social networking, and blogging platforms such as Steemit.

Decentralized applications are often similar to today’s applications, the only difference being that they have a decentralized network. Then, application hosting allows the user to launch and run all decentralized applications in this layer. Without this element, no decentralized application can run on the Internet. The hosting protocol is also completely decentralized. In addition, the maintenance of these hosting servers is entirely secure.

2- Service layer

This layer provides access to essential tools that help you build or run a decentralized application layer. Also, in this layer, it is possible to participate in blockchain control and access off-chain calculations, payment channels (State Channels), data feed ( Data Feed ), and side chain ( Side Chain ).

These sections can be briefly defined as the Data Feed process allowing nodes to receive the most up-to-date information from all sound sources about the network. Off-chain computing allows computational processing to be performed outside of the blockchain network, increasing privacy. Payment channels refer to the communication path between two nodes.

Apart from these elements, there may be other parts in this blockchain layer. Oracles, multiple signatures, smart contracts, digital assets, wallets, distributed file storage memory, digital identities, etc.

3- Semantic layer

The Semantic Layer includes the consensus algorithm, virtual machines, and other requirements for user participation, etc.

The consensus algorithm is necessary for agreement between the blockchain network nodes. Thus, in this process, all nodes must agree to verify information in the network; Therefore, no user can initiate a transaction and add it to the ledger unless they agree with other users to add the block after validating the information. Without a consensus algorithm, the blockchain network loses its meaning. Different types of consensus algorithms have been explained. For example, the first algorithm is called proof of work, and the algorithm for proof of shares and their other derivatives are among the different algorithms used in blockchain.

Participation requirements in this layer refer to the rules that can be used to decide whether new users join the network. This element is used primarily in private blockchain technologies.

The virtual machines in this layer are also embedded in the network to increase the security and execution environment for all tasks. This feature is often used to implement smart contracts.

The sidechains of this layer also allow developers to use separate blockchains to develop decentralized applications so that the core of the leading network is not overshadowed.

4- Network layer

This layer consists of Trusted Execution Environment, RLPx protocol, block delivery network, etc.

A Trusted Execution Environment (TEE) helps the architecture avoid extensibility issues. This feature solves network problems and increases the network’s security. Also, it helps to have storage outside the leading grid to optimize the network load. The RLPx protocol is also a set of network protocols that help exchange information between two users on the blockchain.

5- The infrastructure layer

The last layer in the blockchain technology architecture is the infrastructure layer, which includes three levels hardware, system, and server. Nodes and devices connected to the network will be classified in this layer. Another part of the blockchain in this layer is the network’s decentralized storage memory. Tokens are another component of this layer.

Blockchain fork

One of the exciting parts of blockchain is the forking process. But what is a blockchain fork? Fork in computer science means “branching” and “multi-branching.” To accurately define this concept and understand its process in blockchain, we first go to its roots in software engineering.

In project fork software engineering (Project Fork) or, in other words, project branching occurs when developers separate a copy of the source code from the original software and develop it independently. This process makes software distinct and separate from the original software. Of course, developers should not necessarily create a fork intentionally and with a primary purpose; this process may occur unexpectedly in the software environment.

To understand the concept of blockchain fork, it is necessary to consider the decentralized nature of blockchain. This feature of blockchain means that participants must be able to agree on parts of the blockchain network, including protocols and blocks. This collective agreement among the blockchain network nodes verifies the transactions within each block.

Sometimes, the nodes in the network cannot reach a consensus about the future state of the blockchain. This lack of consensus leads to the creation of various forks, dividing the main chain of blocks into two or more branches, all of which are valid.

There are three types of blockchain forks, which can be divided into subcategories. These three types of divisions occur in different conditions. Blockchain forks are:

1- Soft Fork

In this type of branching, the new protocol is changed to be compatible with the previous one (Backward-Compatible). In this case, the blockchain software that runs on the nodes in the network undergoes a slight change, and the blocks extracted according to the new protocol are also considered valid by the nodes that have the old version of the blockchain. For example, the SegWit update to the Bitcoin network added a new class of addresses to the network known as Bech32. However, adding a new type of talks did not invalidate the previous P2SH addresses, and a node with a P2SH address can have a valid transaction with a node with a Bech32 address.

2- Hard Fork

In this type of blockchain fork, we see a more sweeping change. In this type of branching, the blockchain protocol undergoes a so-called backward-incompatible change. And in other words, the blockchain software changes so that newly mined blocks according to the new protocol will not be validated by the previous version of the blockchain. When a hard fork happens, a new currency is born. For example, Bitcoin Cash was born after the hard fork of Bitcoin.

Nodes that update the hard fork will receive the digital currency of the new version equal to the number of digital currencies they have from the previous version. For example, if someone had 100 Bitcoins and ran a Bitcoin Cash Hard Fork Update, they would receive 100 Bitcoin Cash in addition to the number of Bitcoins.

Another example of hard forks is the update of Casper in Ethereum, which leads to a change in the agreement and consensus protocol of nodes. This update will convert Proof of Work (PoW) to Proof of Stake (PoS).

3- Temporary Fork or Accidental Fork

This fork happens when two miners extract a new block simultaneously, and the entire network may not agree on selecting a new partnership. Some nodes accept the block mined by group A, and some others get the block mined by group B. to abide This general lack of agreement on a partnership, which often occurs due to the time difference, causes the generation of new chains. This type of fork has one or more blocks of the same height.

Random forks are also called temporary forks; Because one of the branches will disappear, and all the nodes will be directed to only one of them.

Blockchain fork applications

In total, there are three primary uses for forks, and since a bunch of knives are done with programming; Therefore, programmers follow a specific goal. These applications include 1- Adding new functionality, 2- Solving security problems 3- Returning infected transactions or returning stolen cryptocurrencies.

Types of blockchain networks

The types of blockchain networks are divided into at least four categories, which are: public blockchain, private blockchain, consortium blockchain, and hybrid blockchain.

Public blockchain

In short, the public blockchain network is a permissionless distributed ledger technology that anyone via the Internet can join, transact, and participate in invalidations. Validation of transactions in this type of network is done through consensus methods with proof of work or proof of stake, etc.

Most blockchain networks consider economic incentives and financial rewards for active users. For example, Bitcoin, Ethereum, Litecoin, and NEO are among these blockchain networks. Voting and fundraising can be mentioned among the applications of public blockchain networks.

Private blockchain

A private blockchain network is a blockchain that runs in a limited environment, has a membership that requires permission, and is controlled by an organization, group, or individual. Therefore, the administrators define access, authority, and how the users operate. This type of network also brings transparency, confidence, and security to selected users.

Of course, due to the need to obtain permission and the existence of the leading managers of the network, this type of blockchain loses the nature of being decentralized. For example, Multichain and Hyperledger Fabric and Corda networks are classified among private blockchain networks.

Private blockchains are used in the supply chain management of organizations, confirmation of ownership of assets, internal voting, etc. The superiority of private blockchain over the public blockchain is in its users’ processing speed and consensus. Also, a private blockchain is more expandable; Because, in this type of network, only a certain number of nodes can validate transactions.

Blockchain Consortium

A consortium blockchain is a type of blockchain that covers the need for public and private blockchain features simultaneously. In a blockchain consortium, parts of organizations will be made public, while others will remain private. For example, several organizations intend to cooperate, and by setting up such a network, they can easily manage the cooperation process.

Predetermined nodes carry out the method of consensus and agreement in the consortium blockchain. But even though attendance is not possible for the general public, it will still be decentralized; Because several separate organizations manage this network.

To ensure the correctness of this type of blockchain operation, the validator node can perform two actions: validating the transaction and initiating or receiving the marketing.

On the other hand, a network member node will only be able to initiate or receive transactions. This type of blockchain is used in banking, payment networks, research, etc. Marco Polo, Energy Web Foundation, and IBM Food Trust can be mentioned among the blockchain networks of the consortium.

Hybrid blockchain

A hybrid blockchain is a network that combines two types of public and private blockchains. Although this type of blockchain may seem similar to the consortium blockchain, their nature has fundamental differences. Users in this network can control people’s access to data stored in the blockchain. In this way, only a part of the network data is open to public access without permission, and the other amount will only be accessible to selected users by obtaining authorization. Hybrid blockchain flexibility allows users to quickly become members of a private blockchain with access to multiple public blockchains.

Transactions on the hybrid blockchain are verified within the network, But users can also transfer it to the public blockchain for verification. Public blockchains make cryptography more complex and involve more nodes for validation; As a result, the security and transparency of the blockchain network will be doubled. Dragonchain and XinFin can be mentioned among the hybrid blockchains.

Sidechain

A sidechain is a side blockchain connected to the blockchain as the main chain in two ways. A sidechain enables the exchange of digital assets at a predetermined rate between itself and the main chain.

Suppose a global decentralized network of several blockchains, each of which has its own rules, goals, and efficiency, and while being independent, they also form a single ecosystem. This single ecosystem consisting of several separate blockchains can be called a sidechain.

This complex cryptographic mechanism allows tokens and other digital assets to move freely between the primary and side chains. A clear example for the chain side is Liquid Network, a consensus platform for exchanges and trading platforms that increase the speed and security of transactions. Since the Liquid network is connected to Bitcoin as its main chain, only activities involving Bitcoin are possible.

Rootstock application is designed with the aim of effective implementation of smart contracts. Side folds are classified in different ways according to their function. For example, even though both Liquid and Rootstock networks are considered sidechains, their use is very other.

Second layer blockchain

Layer 2 (L2) blockchain is generally an umbrella term to describe a specific set of solutions to deal with the scalability problem in traditional blockchains. One of the problems of Bitcoin and Ethereum blockchain networks was the lack of scalability. The reason for the need for scalability is that every node in early blockchain networks was required to process every single transaction.

Therefore, the network activity would increase, the transactions would accumulate, and the throughput rate would decrease. In other words, the higher the scalability, the higher the number of transactions processed per second.

To solve this issue, Ethereum initially allowed users to pay more Gas to prioritize transactions; According to this approach, anyone who spent more Gasfi will raise the priority of their marketing. But, with this method, another problem was created, and like an auction, the price of Gas became more and more when the network was busy.

As a result, it became more expensive to use the network, directly impacting average users. The presence of DeFi and NFT protocols on Ethereum further complicated this process.

Thus, second-layer blockchains emerged.

According to Ethereum’s official website, the second layer blockchain is a separate blockchain based on Ethereum and inherits Ethereum’s security guarantees. The Bitcoin and Ethereum blockchains are first-layer and are the foundation on which various layer two networks (such as the Lightning Network in Bitcoin and rollups in Ethereum) are built.

Ethereum rollups are a solution that users can use to reduce the transaction fee (GasFi) by up to 100% compared to the first layer transactions. In short, rollup works by rolling up 100 transactions into one transaction in the first layer. The benefits of second-layer blockchains include cost reduction, greater security, and expanded use cases.

Modular blockchain

Modular blockchain is a new concept of blockchain types that arose due to scalability problems in integrated blockchains such as Bitcoin and Ethereum. Another solution to facing scalability in integrated blockchain architecture led to the creation of the modular blockchain.

The rapid development of blockchain technology in the last few years has made blockchains such as Ethereum and Bitcoin fall into the category of traditional blockchains. This category of traditional integrated blockchains does all its processing with shared network resources. This way, all full nodes, and verifiers are responsible for all the work from execution to consensus and data accessibility. This volume of operations causes problems for the blockchain network when the network is busy, and transactions increase.

In technology, modular refers to smaller systems that create a larger and more complex system by being placed next to each other. Therefore, a modular blockchain was formed to provide another solution for scalability. A modular blockchain is also considered a piecemeal network consisting of several different layers, which can be used in an outer chain.

For example, the security layer, data accessibility, and execution layer exist separately, which can overlap and be activated or deactivated as needed based on the system’s needs. For example, the Celestia network provided the first modular protocol that could be deployed for a specific purpose. The modular architecture of this network is such that the layers of consensus, data provision, and access are separate from the execution layer.

Application of blockchain

As mentioned, blockchain is reliable for storing information about all transactions. Next, we will examine its uses.

Encrypted digital currency

Blockchain technology provides the foundation for cryptocurrencies such as Bitcoin. The Federal Reserve controls the US dollar. Under this centralized credit system, the user’s data and currencies are technically at the bank’s or local government’s behest.

The user’s private information is hazardous if the bank is hacked. If the bank goes bankrupt or the government of the user’s country of residence is not stable enough, the financial value of the user’s assets will be at risk. These concerns led to the conception and development of Bitcoin in the first place. In 2008 (1387 AD), when some banks ran out of liquidity, a financial rescue plan was implemented partly with the help of taxpayers’ money.

Blockchain now allows cryptocurrencies such as Bitcoin to operate by extending itself across a network of computers without the need for a specific credit center. As a result, possible risks are significantly reduced, and transaction and financial processing fees are also eliminated.

Smart contract

Another application of blockchain is smart contracts. A smart contract is a code built into the blockchain to facilitate and confirm an agreement on a contract or even negotiate terms. The smart contract is executed under the conditions that the users accept. When the necessary needs are met, the clauses of the agreement will be fulfilled automatically.

For example, a tenant plans to rent an apartment through a smart contract. The landlord agrees to send the building code to the tenant once the security deposit is paid. Both parties of the agreement send their desired parts to the smart contract to automatically exchange the code to the apartment by paying the warranty on a specific date. If the landlord does not send the door code by the specified date, the smart contract will also fully automatically return the tenant’s security deposit. In addition to saving time, this process has eliminated the payment of deposit and refund fees.

Banking and financial services

Perhaps no industry will benefit more from applying blockchain technology in its business activities than banking. International financial institutions are active only during office hours and five days a week. Thus, if a person intends to deposit the amount of a check into his account at 6 pm on Friday, this money will not be deposited into his account until Monday morning. Even if the deposit is made during office hours, the transaction confirmation may take up to three days due to the high volume of bank transactions. These are the issues that today’s banking is struggling with.

Video games

Cryptokitties game was launched in November 2017. This game showed how blockchain technology could be used in the video game industry. This game was at the top of the news a month after its launch; Because the character CryptoKitty, a virtual pet in the game was sold at a price of more than 100,000 dollars.

Capital Market

Another application of blockchain technology, according to Santander Bank, is its use in the capital market; Of course, using this technology in the blockchain network is not as easy as using it to transfer money.

Trading

In the blockchain business system developed for trading, each transaction includes a Letter of Credit, through which the buyer and seller ensure the accurate execution of the trade.

Media

Some media outlets are trying to create a content distribution network using blockchain. For example, on the Decent platform, content producers share their products on the blockchain network to find customers. Then, if a buyer is found, the product fee will be paid immediately. Also, Comcast is another blockchain network that allows people to book TV ads.

Energy

Even though blockchain technology consumes a lot of energy, it has all the necessary features for managing energy consumption. For example, in this network, you can define all energy sources, measure each user’s energy consumption, and issue invoices in real-time.

voting

Blockchain technology is democratic; Therefore, with some creativity, it can be used for direct election voting purposes. Among the features suitable for voting in blockchain, we can mention the impossibility of changing the history of transactions, collective security, not tracking users and accessing people’s information, etc.

civil registry

Every country has a civil registry that collects people’s identity information from name to date of birth and death, number of children, etc. This information is constantly growing; As a result, countries face many challenges in managing and maintaining information security. Maybe it’s time to facilitate recording personal information records and their protection using blockchain technology.

Tax

Tax calculation is a time-consuming and heavy process that can be easily managed through blockchain and minimize human error. Especially with the help of this technology, tax evasion can be avoided.

big data

A blockchain is a decentralized database that shares certain information with all active nodes in the network. Now suppose that any data can be stored in it. On the other hand, the possibility of validating and verifying the authenticity of information will also create a revolution in the storage of shared knowledge. For example, we can mention blockchain-based cloud storage services such as STORJ and Sia, which allow users to store files in a decentralized and encrypted manner.

The mechanism of this class of services is that it divides the file into, for example, 80 pieces and keeps each piece encrypted in the space provided by the nodes. To download and access the entire file, it is enough for the user to download, for example, 30 of the 80 pieces. With this method, the security and health of the files will be better maintained.

Health and treatment

Medical institutions can use blockchain to redefine the way they store patient records. This technology allows patient forms to be encrypted in the blockchain so that they are only available to certain people.

Blockchain vulnerabilities and attacks

Like any other phenomenon, blockchain technology is vulnerable and may be subject to attacks. According to published research, more than 40 vulnerabilities threaten blockchain and digital currency platforms. To learn more about blockchain network penetration and hacking, refer to the linked article. Next, we are going to mention some vulnerabilities of the blockchain network.

Blockchain security vulnerabilities are divided into four general categories, each of which has its attacks and hacking scenarios. These four categories are:

1- Peer-to-Peer network-based attacks

• Eclipse attack
• Sybil carried him

2- Attacks based on Ledger and Consensus

• Selfish Mining Attack
• Mining Malware attack
• Attack 51%
• Timejack Attack
• Finney Attack
• Race attack
• Double Spending Attack

3- Attacks based on smart contracts

• DAO campaign

4- Wallet-based attacks

• Carry it Parity Multisig Wallet
• Dusting him

Advantages of blockchain

For all the complexities involved in blockchain, the technology’s capabilities as a decentralized method of record-keeping are almost limitless. Among the advantages of using blockchain, the following can be mentioned:

• Increasing security in privacy
• Reduced payment fees
• We are reducing possible errors because using blockchain increases the accuracy of doing work.
• Network decentralization prevents possible manipulations.
• Transactions are done with complete security and privacy.
• Blockchain performance transparency
• It allows citizens of underdeveloped countries or unstable governments to keep their personal information safe or use its banking services.

Disadvantages of blockchain

• High cost of Bitcoin mining
• The low number of transactions per second
• The possibility of being used in illegal activities and exchanges due to the non-conflict nature of transactions
• Government laws and regulations about digital currency

The future of blockchain

Blockchain technology has created many surprises, and it is not far from the mind that it will make many impossible things possible shortly. International financial transfers can be done in a few hours instead of several days and then down to a few minutes. Maybe in the future, we will see that self-driving electric cars and drones will use the blockchain network to pay for services such as charging stations and landing sites.

Predicting the growth path of blockchain is much more complex than one might think. Forecasters often overestimate future events’ speed and ignore the events’ long-term effects. Did anyone notice the rise and growth of social networks? Who would have indicated that clicking pictures of our friends’ faces would replace spending time watching TV?

But the capabilities of the blockchain industry suggest that future changes will be as significant as the original invention of the Internet.

 What we can be sure of is the maturity of blockchain technology and its rooting in all areas of human life in the future. Considering the long way it has traveled in just ten years, more significant events will appear sooner than we think.