What is blockchain? Its advantages and disadvantages and its applications in life

If you’ve been following banking, investing, or cryptocurrencies for the past ten years, you are probably familiar with blockchain on the network, the record-keeping technology behind bitcoin. And there’s a good chance it just makes so much sense. When trying to learn more about blockchain, you may have come across a definition like this: blockchain is a decentralized, distributed ledger. “The good news is, blockchain is actually easier to understand than it sounds.

What is blockchain?

If the technology is too complicated, why call it blockchain? At its most basic level, blockchain is really just a chain of blocks, but not in the traditional sense of those words. When we say words about block and blockchain in this context, we are really talking about digital information (block) stored in a public database (chain).

Blocks on blockchain are made up of pieces of digital information. Specifically, they have three parts:

  1. Block information about transactions, showing the date, time, and dollar amount of your most recent purchase from Amazon.
  2. Block stores information about who are participating in the transaction. A block for your purchase from Amazon records your name along with Amazon.com. Instead of using your real name, your purchase is recorded without any identifying information using a unique digital signature, a type of username.
  3. Blocks store information that distinguishes them from other blocks. Just like you and I have a name to distinguish us from each other, each block stores a unique code called a hash, which allows us to distinguish it from every other block. Tell you you made a purchase on Amazon, but while it’s in transit you decide that you can just resist and need a second. While the details of your new transaction look almost identical to your previous purchase, we are still able to differentiate blocks because of their unique tokens.

While the block in the example above is being used to store a purchase from Amazon, the reality is a bit different. A single block on the blockchain can actually store up to 1 MB of data. Depending on the size of the transactions, that means a block can hold several thousand transactions under one roof.

How does blockchain work?

When a block stores new data, it is added to the blockchain. Blockchain, as its name implies, consists of many blocks that are strung together. However, for a block to be added to the blockchain, four things must happen:

  1. A transaction must happen. Let’s continue with the example of an impulse purchase on your Amazon. After hastily clicking through multiple payment prompts, you go against your better judgment and purchase.
  2. That transaction must be verified. After making that purchase, your transaction must be verified. For other public information records, like the Securities and Exchange Commission, Wikipedia or your local library, there’s someone in charge of checking new data entries. With blockchain, however, that work is reserved for a network of computers. These networks typically consist of thousands (or in Bitcoin’s case, around 5 million) computers spread across the globe. When you make a purchase from Amazon, that network of computers hastily checks to see if your transaction is happening the way you say it. That is, they confirm the details of the purchase, including the transaction’s time, amount, and participant in the transaction.
  3. The transaction must be stored in a block. Once your transaction is verified as correct, it will be given a green light. The transaction’s dollar amount, your digital signature, and Amazon’s digital signature are all stored in one block. There, the transaction will likely join hundreds, or thousands of others liking it.
  4. That block must be given a hash function. Unlike an angel who earns his wings, once all block transactions have been verified, it must be provided with a unique identifier, called a hash. This block is also given the hash of the block most recently added to the blockchain. Once hashed, the block can be added to the blockchain.

When that new block is added to the blockchain, it becomes public to everyone – even you. If you take a look at Bitcoin’s blockchain, you will see that you have access to transaction data, along with information about when (playtime), in which (highways) and by whom (transfers followed by) is added to the blockchain.

Types of Blockchain

The Blockchain system is divided into 3 main categories:

Public

Anyone has the right to read and write data on Blockchain. The process of validating transactions on this Blockchain requires thousands or tens of thousands of nodes. Therefore, to attack this Blockchain system is impossible because the cost is quite high. Examples: Bitcoin, Ethereum.

Private

Users are only allowed to read data, not write permission because this belongs to an absolutely trusted third party. This organization may or may not allow users to read data under certain circumstances. The third party has the sole discretion to decide any changes on the Blockchain. Since this is a Private Blockchain, the transaction confirmation time is quite fast because only a small number of devices are required to validate the transaction. For example, Ripple is a Private Blockchain, this system allows 20% of the nodes to be fraudulent and only the remaining 80% to operate stably.

Permissioned

Also known as Consortium, a form of Private but adds a certain number of features, combining “belief” when participating in Public and “absolute trust” when participating in Private. For example: Banks or joint venture financial institutions will use Blockchain for themselves.

Versions of Blockchain

Blockchain 1.0 – Money and Payment

The main application of this version is cryptocurrency: includes currency conversion, remittances and the creation of digital payment systems. This is also the area most familiar to us that sometimes quite a lot of people mistake Bitcoin and Blockchain as one.

Blockchain 2.0 – Finance and Markets

Banking and financial processing: scaling Blockchain, bringing in financial and market applications. Assets include stocks, checks, debt, title and anything related to an agreement or a contract.

Blockchain 3.0 – Design and Monitor Operations

Bringing Blockchain beyond financial borders, and into fields like education, government, health, and the arts. In these areas, there will be multiple types like physical, digital or human in nature.

Consensus mechanism in Blockchain

The consensus mechanism in Blockchain can be understood as the way in which Byzantine generals can reach consensus to win together. The following are common types of consensus mechanisms:

Proof of Work

Popular in Bitcoin, Ethereum, Litecoin, Dogecoin and most cryptocurrencies. Consumes quite a lot of electrical energy.

Proof of Stake

Popular in Decred, Peercoin and in the future is Ethereum and many other cryptocurrencies. More decentralized, consumes less energy and is not easily intimidated.

Delegated Proof-of-Stake.
Popular in Steemit, EOS, BitShares. Cheap transaction costs; extendable; high energy efficiency. However, there is still a bit of focus because this algorithm selects a trusted person to authorize.

Proof of Authority.
This is a centralization model commonly seen in POA.Network, Ethereum Kovan testnet. High performance, good scalability.

Proof-of-Weight (Proof of Mass / Greater is better)

  • Popular in Algorand, Filecoin. Customizable and well scalable. However, the development process will be a big challenge.
  • Byzantine Fault Tolerance (Byzantine Anti-Fraud Consensus Byzantine Generals Siege Blockchain).
  • Popular in Hyperledger, Stellar, Dispatch, and Ripple. High productivity; low cost; extendable. However, it is still not completely reliable.

This algorithm has 2 versions:

Practical Byzantine Fault Tolerance (Anti-fraud consensus / Byzantine General surrounded Blockchain in practice).
Federated Byzantine Agreement (Byzantine Alliance by Consensus).
Directed Acyclic Graphs (Topological Algorithm).
Often seen in Iota (Tangle technology), Hashgraph, Raiblocks / Nano (Block-lattice technology), is a competitor of Blockchain.

Main features of BlockChain

A distributed database

Imagine a spreadsheet that is duplicated thousands of times through a network of computers, which is designed to update the spreadsheet on a regular basis so that you can understand the basics of blockchain.

Information held on a blockchain exists as a continuously harmonized and shared database. Here’s how to use the network with obvious benefits. The blockchain database is not stored in a single location, meaning that the records are stored in a public, easy to verify. No centralized version of this database exists, so hackers have no chance of attacking it either. Blockchain is stored by millions of computers at the same time, its data can be accessed by anyone on the Internet.

Blockchain sustainability

Blockchain technology is like the Internet because it has a built-in power. By storing the same blocks of information on its network, blockchain cannot:

Controlled by any one entity

There is no single flaw or error.

Bitcoin was released in 2008, ever since, the Bitcoin blockchain has been operated, operating without any significant disruption. To this point, any problems related to Bitcoin are caused by hacking or poor management. In other words, these problems come from bad intentions and human error, not Bitcoin’s own flaws.

The internet has proven durable for nearly 30 years. This is a good track record for blockchain technology as it continues to be developed

A network of nodes

A network of computational nodes that make up the blockchain. The node here is a computer connected to the blockchain network that uses a client to confirm and forward transactions. The node will receive a copy of the blockchain, which is loaded automatically when joining the blockchain network.

Together, these nodes create a powerful tier 2 network, a completely different perspective on how the Internet might work. Each node is an “administrator” of the blockchain network and automatically participates in the network, the driving force for this participation is the chance to win Bitcoin.

Nodes are also known as Bitcoin mining, but the terminology is a bit misleading. In fact, each of them is competing for Bitcoin by solving puzzles. Bitcoin has been the “life” of blockchain since its inception. Bitcoin is only being recognized as a very small part of the potential of blockchain technology.

Security

By storing data on its network, blockchain eliminates the risks associated with centrally organized data. Its network has no vulnerabilities. Meanwhile, the security issue on the Internet is becoming more and more complex. We all rely on the username / password system to protect our identities and assets online, but the system is still more likely to break. Blockchain’s security method uses encryption technology with public / private key pairs. The public key (a long string of random numbers) is the address of the user on the blockchain.

Bitcoin sent over the network will be recognized as belonging to that address. The private key is like a password, allowing the holder to gain access to Bitcoin or other digital assets. Store data on the blockchain and it will not be damaged. This is true, although protecting your digital assets will require the security of your private key by printing it out, creating a digital wallet to hold like a paper wallet.

Transparent and unbreakable

The blockchain network exists in a state of agreement, checking automatically every 10 minutes. A kind of digital value self-controlled ecosystem, the network will regulate every transaction that happens in about 10 minutes. Each of these groups of transactions is called a block. Two important features are drawn from here:

  • Transparency: Data is embedded in the network as a public, block.
  • It cannot be corrupted: Changing any unit of information on the blockchain means using a large number of computers to overwrite the entire network.
  • In theory, this could happen. In fact, it doesn’t happen. For example, controlling the system to take over Bitcoin will ruin its value.

The idea of ​​decentralization

By design, blockchain is a decentralized technology. Whatever happens on it is a function of the network. Some important suggestions stem from this. By creating a new way to confirm transactions aspects of traditional commerce may become unnecessary. Transactions on the stock market, for example, can be carried out on the blockchain at the same time, or can be stored as a red book, completely public. And the decentralization has come true.

The global computer network uses blockchain technology to jointly manage the database and record Bitcoin transactions. That is, Bitcoin is managed by its network and no one is central. Decentralized means the network operates on a user basis, or P2P. Possible forms of collective cooperation have only just begun to be explored.

Is blockchain private?

Anyone can view the content of the blockchain, but users can also choose to connect their computer to the blockchain network. In doing so, their computers receive a copy of the blockchain that is updated automatically every time a new block is added, just like a Facebook news feed that updates live every time a new state is available. to post.

Every computer in the blockchain network has its own copy of the blockchain, which means there are thousands or, in Bitcoin’s case, millions of copies of the same blockchain. Although every copy of the blockchain is identical, spreading that information across a computer network makes it harder to manipulate. With blockchain, having a single, definitive account of events can be manipulated. Instead, a hacker would need to manipulate every copy of the blockchain on the network.

However, looking through the Bitcoin blockchain, you will notice that you do not have access to identify information about the user making the transaction. Although transactions on the blockchain are not completely anonymous, personal information about users is limited to their digital signature or username.

This raises an important question: if you cannot know who is adding blocks to the blockchain, how can you trust the blockchain or the computer network that sustains it?

Is blockchain secure?

Blockchain technology for security and trust issues in many ways. First, new blocks are always stored linearly and over time. That is, they are always added to the end of the blockchain game. If you look at the Bitcoin blockchain, you will see that each block has a position on the chain, called the height of the user. At the time of writing, the most recent block’s height was 548,015, meaning it was block 548,015 to be added to the blockchain.

Once a block has been added to the end of the block chain, it is difficult to go back and change the content of the block. That’s because each block contains its own hash, along with the hash of the block before it. Hash codes are generated by a mathematical function that turns digital information into a string of numbers and letters. If that information is edited in any way, the hash code changes as well.

Here, why is that so important to security. Let’s say a hacker tries to edit your transaction from Amazon so that you actually have to pay for your purchase twice. As soon as they edit the dollar amount in your transaction, the block hash will change. The next block in the chain will still contain the old hash, and the hacker will need to update that block to hide their traces. However, doing so will change that block of hash.

Then, to change a single block, a hacker would need to change every single block after that block. Recalculating all those hashes will take a huge amount of computation power. In other words, once a block is added to the blockchain, it becomes very difficult to edit and impossible to delete.

To solve the problem of trust, blockchain networks deployed experiments for computers that wanted to join and add blocks to the chain. The tests, known as the user consensus model, directly require users to prove themselves before they can join the blockchain network. One of the most common examples used by Bitcoin is called proof of work.

In proving the system works, the computers have to prove that they have done Google’s job by solving a complex computational problem. If a computer solves one of these problems, they become eligible to add a block to the blockchain. But the process of adding blocks to the blockchain, what the crypto world calls network mining, is not easy. In fact, according to blockchain news site BlockExplorer, the rate of solving one of these problems on the Bitcoin network is around 1 in 7 trillion at the time of writing. To solve the complex math problems of those odds, computers have to run programs that consume a considerable amount of energy and energy.

The proof of work doesn’t make the hacker attacks impossible, but it makes them somewhat useless. If a hacker wanted to coordinate an attack on the blockchain, they would need to solve complex computational problems at a scale of 1 in 7 trillion like everyone else. The cost of organizing such an attack will almost certainly far outweigh the benefits.

What is the difference between Blockchain and Bitcoin?
The goal of blockchain is to allow digital information to be recorded and distributed, but not edited. That concept can be difficult to cover our heads without seeing the technology work, so let’s see how the earliest application of blockchain technology actually works.

Blockchain technology was first sketched in 1991 by Stuart Haber and W. Scott Stornetta, two researchers who wanted to implement a system where the document timestamp could not be tampered with. But that was not until almost two decades later, with the launch of Bitcoin in January 2009 that the blockchain had its first real-world application.

The Bitcoin protocol is built on the blockchain. In a research article introducing the digital currency, fake Bitcoin creator Satoshi Nakamoto called it a new cryptocurrency system, which is fully peer-to-peer, with no trusted third parties.

Here, how it works.

You have all these people, all over the world, who have Bitcoin. According to a 2017 study by the Cambridge Center for Alternative Finance, the number could reach 5.9 million. Let’s say one out of 5.9 million people wants to spend their Bitcoin on groceries. This is where blockchain comes in.

When it comes to printed money, the use of printed money is regulated and verified by a central authority, usually a bank or government – but Bitcoin is not controlled by anyone. Instead, transactions carried out in Bitcoin are verified by a network of computers.

When one person pays another for goods in Bitcoin, computers on the Bitcoin network race to verify the transaction. To do so, the user runs a program on their computer and tries to solve a complex mathematical problem, called a transaction hash. The completed transaction is recorded and publicly stored as a block on the blockchain, at which point it becomes immutable. In the case of Bitcoin and most other blockchains, computers successfully verify blocks that are rewarded for their labor in cryptocurrency.

Although transactions are publicly recorded on the blockchain, user data is not – or, at least, incomplete. In order to make transactions on the Bitcoin network, participants must run a program called wallets. Each wallet consists of two unique and separate cryptographic keys: a public key and a private key. The public key is the location where transactions are deposited and withdrawn from. This is also the key that appears on the blockchain ledger as the user’s digital signature.

Even if a user receives a Bitcoin payment to their public key, they will not be able to withdraw them with their private partner. A user’s public key is a reduced version of their private key, generated through a complex mathematical algorithm. However, due to the complexity of this equation, it is almost impossible to reverse the process and generate the public key private key. For this reason, blockchain technology is considered confidential.

Public key and private key ELI5

You can think of a public key as a field key and a private key as a combination of keys. Teachers, students and even your lover can insert letters and notes through the opening in your locker. However, the only person who can access the contents of the mailbox is the person with the unique key. However, it should be noted that while the school’s key combinations are kept in the main office, there is no central database keeping track of the private keys of the blockchain network. If a user mistakenly sets their private key, they lose access to their Bitcoin wallet, which is considered a bonus for Bitcoin holders.

In the Bitcoin network, blockchain is not only shared and maintained by a public network of users – it is also negotiated. When a user joins the network, their connected computer receives a copy of the blockchain that is updated whenever a new block of transactions is added. But what if, through human error or the attempt of a hacker, a user of a copy of the blockchain is manipulated to be different from every other copy of the blockchain?

The blockchain protocol discourages the existence of multiple blockchains through a process called Google consensus. With the presence of many different copies of the blockchain, the consensus protocol will adopt the longest chain available. More users on a blockchain means blocks can be added to the end of the chain faster. According to that logic, the blockchain of record will always be the thing most trusted by the user. The consensus protocol is one of blockchain technology’s greatest strengths, but also allows for one of its biggest weaknesses.

Theoretically, hackers can take advantage of the majority rule in a 51% attack. Here’s how it would happen. Let’s say there are 5 million computers on the Bitcoin network, which is definitely not enough but one number is easy to divide. To gain a majority on the network, a hacker would need to control at least 2.5 million and one of those computers. In doing so, an attacker or group of attackers can interfere with the process of recording new transactions. They can send a transaction – and then reverse it, making it appear as if they still have the coins they just spent. This vulnerability, known as double spend, is the digital equivalent of a perfect counterfeit and will allow users to spend their Bitcoin twice.

Such an attack is extremely difficult to execute against a blockchain of Bitcoin size, as it would require an attacker to gain control of millions of computers. When Bitcoin was first established in 2009 and its number of users was numbered in the tens, it would be easy for an attacker to control the majority of the computing power in the network. This defining feature of blockchain has been flagged as a weakness for fledgling cryptocurrencies.

Users fearing 51% attacks could actually limit the monopoly that forms on the blockchain. In “Digital Gold: Bitcoin and the Inner Story of the Lost and Millionaires Trying to Reinvent Money” (English: Digital Gold: Bitcoin and the Inside Story of the Misfits and Millionaires Trying to Reinvent Money) New York Times journalist Nathaniel Popper writes about how a group of users, known as Bit Bitury, together create thousands of high-powered computers a competitive edge on blockchain. Their goal was to mine as many blocks as possible and earn bitcoins, which at that time was worth about $ 700 per block.

However, by March 2014, Bitfury was positioned to exceed 50% of the total computing power of the blockchain network. Instead of continuing to increase their holdings online, the group was elected to self-regulate and vowed never to exceed 40%. Bitfury knows that if they choose to continue to increase control of their network, the value of bitcoin will decrease as users sell off their funds in response to the possibility of a 51% attack. In other words, if the user loses trust in the blockchain network, the information about that network risk becomes completely worthless. Blockchain users can then only increase their computing power to a point before they start to lose money.

How can blockchain be used in the real world?

Blocks on the blockchain store data about currency transactions – we’ve eliminated that. But it turns out that blockchain is actually quite a reliable way of storing data about other types of transactions. In fact, blockchain technology can be used to store data about asset exchanges, stop in the supply chain, and even vote for a candidate.

Deloitte recently surveyed 1,000 companies across seven countries about integrating blockchain into their businesses. Their survey shows that 34% already have a blockchain system in production today, while another 41% are expected to deploy a blockchain application within the next 12 months. Additionally, nearly 40% of the companies surveyed reported that they would invest $ 5 million or more in blockchain over the next year. Here are some of the most popular uses of blockchain that are being explored today.

Bank

Perhaps no industry has benefited more from integrating blockchain into its business than banks. Financial institutions operate only during business hours, five days a week. That means if you try to deposit a check on a Friday at 6pm, you will likely have to wait until Monday morning to see that money hit your account. Even if you make a deposit during business hours, the transaction can still take 1-3 days to verify due to the sheer volume of transactions banks need to settle. Blockchain is different, never sleeps. By integrating blockchain into a bank, consumers can see their transactions processed in at least 10 minutes, essentially the time it takes to add a block to the blockchain, regardless of time or day of the day. week. With blockchain, banks also have the opportunity to exchange money between institutions more quickly and securely. In stock trading, for example, the clearing and settlement process can take up to three days (or longer, if banks do international transactions), meaning money and stocks are frozen in that time.

Given the size of the funds involved, even within a few days the money is transferred can bring significant costs and risks to banks. Santander, a European bank, places potential savings at $ 20 billion per year. Capgemini, a French consultant, estimates that consumers can save up to $ 16 billion in banking and insurance fees each year through blockchain-based applications.

Given the size of the funds involved, even within a few days the money is transferred can bring significant costs and risks to banks. Santander, a European bank, places potential savings at $ 20 billion per year. Capgemini, a French consultant, estimates that consumers can save up to $ 16 billion in banking and insurance fees each year through blockchain-based applications.

Cryptocurrencies

Blockchain forms the foundation for cryptocurrencies like Bitcoin. As we discovered earlier, currencies like the US dollar are regulated and verified by a central authority, usually banks or governments. According to the central authority system, the user’s data and currency are technically anytime their banks or governments. If a user bank collapses or they live in a country with unstable government, the value of their currency is at risk. These are the worries about Bitcoin being born. By spreading its operations across a network of computers, blockchain allows Bitcoin and other cryptocurrencies to operate without the need for a central authority. This not only reduces risk, but also eliminates many processing and transaction fees. It also gives people in non-volatile countries a more stable currency with more applications and a wider network of individuals and organizations with which they can trade, both in country and international (at least, this is the goal.)

Health care

Healthcare providers can leverage blockchain to securely store their patient records. Once a medical record is created and signed, it can be written to the blockchain, providing the patient with evidence and confidence that the record cannot be altered. These personal health records can be encrypted and stored on the blockchain using a private key, so they can only be accessed by a limited number of individuals, thus ensuring privacy.

Property records

If you’ve ever gone to the ward to do paperwork, you’ll know that the claiming process is both cumbersome and ineffective. Today, an actual deed must be sent to a government employee at the ward, where it is manually entered into the ward’s central database and public index. In the case of a property dispute, the claims against the property must be compared with the publicity index. The process is not only costly and time consuming – it is also deceived by human error, where each inaccuracy makes tracking property ownership ineffective. Blockchain has the potential to eliminate the need to scan documents and track physical files on the ward. If ownership of an asset is stored and verified on the blockchain, the owner can be confident that their actions are accurate and permanent.

Smart contract

A smart contract is a computer code that can be built into a blockchain to facilitate, verify, or negotiate a contract agreement. Smart contracts work under a set of conditions that the user agrees to. When those conditions are met, the terms of the agreement will be executed automatically.

For example, I rented you my apartment with a smart contract. I agree to provide you with the apartment door number as soon as you pay me the security deposit. We will both send a portion of our agreement to the smart contract, which will keep and automatically exchange my door code for your security deposit on the rental date. If I do not provide the door code before the rental date, the smart contract will refund your deposit. This eliminates the fees commonly associated with using a notarized or third-party mediator.

Supply chain

Vendors can use blockchain to record the source of documents they purchased. This will allow companies to verify the authenticity of their products, along with health and ethics marks.

Vote

Voting with blockchain has the potential to eliminate electoral fraud and increase voter turnout, as was tested in the November 2018 midterm elections in West Virginia. Each vote will be stored as a block on the blockchain, making them nearly impossible to tamper with. The blockchain protocol will also maintain transparency in the electoral process, reduce the staffing needed to conduct elections, and provide officials with instant results.

What are the advantages of Blockchain?

For all its complexity, the potential for blockchain, as a decentralized form of record storage, is almost limitless. From greater user privacy and enhanced security, to lower processing fees and fewer errors, blockchain technology can very clearly see applications beyond those outlined above. Here are the blockchain selling points for businesses on the market today.

Accuracy

Transactions on a blockchain network are approved by a network of thousands or millions of computers. This eliminates nearly all human involvement in the verification process, resulting in fewer human errors and a more accurate record of information. Even if a computer on the network makes a computational error, the error will only happen with one copy of the blockchain. In order for that error to spread to the rest of the blockchain, it needs to be done by at least 51% of the network’s computers – something impossible.

Price

Usually, consumers pay a bank to verify a transaction, a notary to sign a document or a minister to perform a marriage. Blockchain eliminates the need for third-party verification and, with it, their associated costs. Business owners incur a small fee whenever they accept credit card payments, for example, because banks have to process those transactions. Bitcoin, on the other hand, has no central authority and virtually no transaction fees.

Decentralization

Blockchain does not store any of its information in a central location. Instead, the blockchain is copied and spread across a network of computers. Whenever a new block is added to the blockchain, every computer on the network updates its blockchain to reflect the change. By spreading that information over a network, instead of storing it in a central database, the blockchain becomes more difficult to tamper with. If a single copy of the blockchain falls into the hands of a hacker, a single copy of information, rather than the entire network, will be compromised.

High efficiency

Transactions placed through a central authority can take up to several days to process. For example, if you try to deposit a check on a Friday night, you might not actually see the funds in your account until Monday morning. While financial institutions operate during business hours, five days a week, blockchain operates 24 hours a day, seven days a week. Transactions can be completed in about ten minutes and can be considered secure in as little as a few hours. This is especially useful for cross-border transactions, which often take longer due to time zone issues, and the fact that all parties have to confirm payment processing.

Private

Many blockchain networks act as public databases, meaning anyone with an internet connection can see a list of the network’s transaction history. While users can access details about transactions, they cannot access identifying information about the users making those transactions. It is a common misconception that blockchain networks like bitcoin are anonymous, when in reality they are just secrets. That is, when users conduct public transactions, their unique code called the public key is recorded on the blockchain, instead of their personal information. Even though a person’s identity is still linked to their blockchain address, this prevents hackers from obtaining the user’s personal information, as could be the case when banks are hacked.

Protect

Once a transaction is recorded, its authenticity must be verified by the blockchain network. Thousands or even millions of computers on the blockchain rush to confirm that the purchase details are correct. After a computer has validated the transaction, it is added to the blockchain as a block. Each block on the blockchain contains its own unique hash, along with the unique hash of the block before it. When information about a block is edited in any way, that block of hash code changes – however, the hash code on that block will not be changed. This discrepancy makes information about the blockchain extremely difficult to change without prior notice.

Transparency: although personal information on the blockchain is kept private, the technology itself is almost always open source. That means users on the blockchain network can modify the code as they see fit, as long as they have the majority of the network’s computing power. Keeping data on blockchain open source also makes data tampering much more difficult. With millions of computers on the blockchain network, for example, at any given moment, surely no one can make a change unnoticed.

What are the disadvantages of Blockchain?

Despite significant strides towards blockchain, there are also significant challenges to its adoption. The barrier to the application of blockchain technology today is not just technical. Most of the challenges are really political and regulatory, saying nothing for the thousands of hours of custom software design and back-end programming required to integrate blockchain into existing business networks. Here are some of the challenges of how blockchain is widely adopted.

Price

While blockchain can save users money in transaction fees, the technology is not free. For example, the proof of work of the system Bitcoin uses to validate transactions consumes a large amount of computational power. In the real world, the power from millions of computers on the bitcoin network is close to what Denmark consumes every year. All that energy costs money, and according to a recent study from research firm Elite Fixture, the cost of mining a single bitcoin varies significantly by location, from just $ 531 to a worthy $ 26,170. amazing. Based on average US utility costs, that figure is closer to $ 4,758. Despite the cost of mining bitcoin, users continue to increase their electricity bills to validate transactions on the blockchain. That’s because when miners add a block to the bitcoin blockchain, they are rewarded with enough bitcoins to make their time and energy worthwhile. However, when it comes to blockchains that do not use cryptocurrencies, miners will need to be paid or incentivized to validate transactions.

Inefficient

Bitcoin is a perfect case study for blockchain’s possible inefficiency. Bitcoin’s proof of work takes about ten minutes to add a new block to the blockchain. At that rate, it was estimated that the blockchain network could only manage seven transactions per second (TPS). Although other cryptocurrencies like Ethereum (20 TPS) and Bitcoin Cash (60 TPS) outperform bitcoin, they are still limited by blockchain. The legacy brand visa, for context, can handle 24,000 TPS.

Private

While the security on the blockchain network protects users from hacking and protects privacy, it also allows for illegal transactions and activities on the blockchain network. The most cited example of blockchain being used for illegal transactions is perhaps Silk Road, a dark online marketplace that operated from February 2011 to October 2013 when the FBI arrested. website owner. The website allows users to browse the website without being tracked and make illegal purchases in bitcoin. Current US regulations prevent users from exchanging online, like those built on blockchain, from complete anonymity. In the United States, online exchanges must obtain information about their clients when they open accounts, verify the identity of each client, and confirm that the client does not appear in any list of nests. any known or suspected terrorist organization.

Protect

Several central banks, including the Federal Reserve, the Bank of Canada and the Bank of England, have opened investigations into digital currencies. According to the Bank of England Research Report February 2015, further research will also be required to create a system that can use distributed ledger technology without compromising currency controls. central bank protection and system protection against system attacks.

Hypersensitivity

Newer cryptocurrencies and blockchain networks are vulnerable to 51% attacks. These attacks are extremely difficult to execute due to the computational power required to gain control of a majority of the blockchain network, but Joseph Boneau, NYU computer science researcher, said that could change. Boneau published a report last year estimating that 51% of attacks were likely to increase, as hackers can now simply hire computing power, instead of buying all the devices.

What’s next for Blockchain?

First proposed as a research project in 1991, blockchain is comfortably settling in its twenties. Like most millennia, blockchain has seen its fair share of the past two decades, with businesses around the world speculating about what the technology is capable of and where it is. looking forward in the coming years.

With many practical applications for the technology being deployed and explored, blockchain finally made a name at the age of twenty-seven, in no small part because of bitcoin and cryptocurrency. As a buzzword on every investor’s tongue in the country, blockchain stands out to make business and government more accurate, efficient and secure.

As we prepare to enter the third decade of blockchain, it is no longer a question of “if” the legacy companies will catch up with the technology – it’s a question of “when”.

What is a digital contract

In this post, we will build on the idea of ​​using digital puzzles as a way to reproduce the scarcity and on the importance of supply control mechanisms to provide durability for cryptocurrencies. digital, from which the concepts of proof of ownership are discovered through signatures as well as writing, and the technique is called CoinJoin.

Proof of ownership: Signature

The second Plan B brought us was to focus on the human theme and to describe the question “Who is it?”.

You have rules set up for releasing new sats, but what about their transfer? Who is allowed to change the general balance sheet data and transfer ownership?

If there is a central authority responsible for reallocating the sats, follow the instructions of the current owner (it is possible to log into the system by accessing the usual username and password, similar to in the test There will be Mallory making you vulnerable to failure again: Why bother then switching from physical gold to PoW-based digital scarcity? On the other hand, if each user has equal rights to redefine ownership then your system is completely inoperable: People will be encouraged to continually transfer the sats of others to themselves. You need some sort of consistent authority protocol that people can independently audit.

The solution is an encryption technique known as a “digital signature”. It works like this: First, Alice chooses a random number called the “secret private key”, where she will keep absolute secret. She then passed this figure through a special mathematical function, easy to apply in one direction but practically irreversible. The result is a different number called the “public key”, which Alice keeps no secret: Instead, she guarantees that Bob will know about it. In the end, she passed the private key and the message through the second function was also difficult to reverse, resulting in a very large number called the “user’s signature”. A third and final mathematical function can be applied by Bob to Alice’s message, signature, and public key, resulting in either positive or negative verification. If the result is positive, he can be sure that Alice has authorized the message “authentication, which means she will then be unable to deny the authorization” the non-denial message. “(Non-repudiation) and the message is not changed in passing” integrity “(integrity).

In other words, it resembles a handwritten signature that is easy for everyone to test on some public sample, but difficult to copy if not the owner of the correct hand. Or wax stamp: easy for everyone to check against a public seal registry, but difficult to copy without the exact wax mold.

So you alter your protocol to create independent reusable proof of work fractions through digital signatures. The first model you deploy is considered trivial: Each user independently creates a private key and creates a public “account”, labeled with the corresponding public key. When a user wants to transfer ownership, they create a message that includes their account along with the recipient’s account and the number of sats they want to transfer. They then digitally sign and distribute it while everyone can verify.

What’s quite interesting is that a similar scheme can be used by many well-known (but possibly fake) developers to sign different versions of software so they can freely change and improve. , repair, update, test, review it and any end user of your system can independently verify signatures before operating their preferred version, leveraging a network The reliability mesh is scaled and fragmented, without the need for a single software delivery agency. This process allows for proper code hierarchy.

Script and “smart contract”

You don’t want to limit rules that every colleague must check before accepting any balance sheet changes, merely the validity of digital signatures.

You decide that each message can also include a “script”: a list of instructions describing additional conditions that the recipient account (or account) will have to meet in order to spend it again. . For example, the sender might request some secret key combination (merge or split) or specific time spent before spending. Starting with these very simple (and easy to audit) things, being able to build complex smart contracts that make and moreover make money effectively “programmable” (programmable) right even without central parties.

The problems of “darknes” and scaleness

Unlike an encrypted messaging system (in which if Alice sends Bob some messages, only Bob can read them), your plan isn’t really optimized for “darkness” ( if Alice sends sats to Bob, her message will have to be revealed outside of Bob’s reach – at least to those who will receive the same sats later).

Circulating money? Payee cannot trust any money transfer (even if duly signed) if they cannot verify that the transfer has actually been transferred to that particular payer, and vice versa, back to the first PoW-based issuance. With a sufficient number of circulating sats, active colleagues will be aware of a large number of past transactions, and legal analysis techniques can be used to statistically correlate quantity and time. , metadata and accounts, thereby eliminating many of their rejection.

Smart contracts can make this problem worse because specific spending conditions are used to define specific software implementations or separate organizational policies.

This lack of “shadow” is more serious than your previous e-gold impact test: Yes, before that, you stored most of your transaction data on your central servers, but Only you, at least as opposed to anyone who has visited (including many Mallory dealerships). Furthermore, you can implement some highly advanced coding strategies to make yourself at least a blind part of what is actually happening among your users.

There’s also a small scale issue associated with this design: The sizable digital signature and the transfer chain the payee needs to receive to validate everything will include multiple signatures, causing the validation can become more expensive. Furthermore, the account change is quite difficult to confirm in parallel.

A new model: “CoinJoin”

In order to mitigate similar problems, you decide to change the underlying entities of the model from bank “accounts” to a “Unspent Transaction Outputs (UTXOs). .

Instead of instructions for moving sats from one account to another, each message now includes a list of old UTXOs, coming from past transactions, and “used” components. And a list of new UTXOs that have “made” products and are ready for future trading. Instead of publishing a private or public key to be used as a general reference (like an IBAN bank or email address), Bob must provide a new, one-time public key for each payment. he wants to receive. When Alice pays him, she signs a message that “unlocks” sats from a previously generated UTXO number and locks it again on a new UTXO number.

As with actual cash, spendable bills do not always match the payment requirement – often requiring change. For example, if Alice wants to pay 1,000 sats to Bob, but she only controls one number of 700 sats UTXOs for each, she will sign a transaction that consumes two of those 700 UTXO sats (unlocking a total of 1,400 sats) and creates two new UTXOs: one associated with Bob’s keys which is the payment key (1,000 sats) and the other associated with Alice’s keys as the change key (400 sats).

Provided people aren’t using reusable keys for different payments, this design adds a “shadow” to itself. But even more so when your users begin to realize that UTXOs consumed and generated by a single transaction don’t have to come from two entities. Alice can create a spend message for old UTXOs she controls and create new UTXOs (linked to Bob), then she can pass that message on to Carol, who just needs to add the old UTXOs which she wants to use and the new UTXOs (linked to Daniel) want to create. In the end, Alice and Carol both signed and distributed the synthesis message (returning both Bob and Daniel).

This particular use of the UTXO model is called “CoinJoin”. (Activation warning: In actual Bitcoin history, this use was not the reason Satoshi’s design for the UTXO model itself but was discovered by other developers as a potential turning point years later. at launch). It disrupts the ability to statistically link the outputs, while preserving what is known as “atomicity”: Transactions are completely valid or invalid, so Alice and Carol cannot. mutual trust. (If one of them tries to change the partially signed message before adding their own signature, the current signature will be invalid.)

There’s one change going on to your system that can really improve the situation even further: another digital signature scheme replaces the currently used digital signature system, that is “Linear in signatures”. That means: when receiving two private keys (nothing but two numbers), sign the same message together and add the signature results together (nothing but two very large numbers) The result is that the correct signature corresponds to the sum of the two public keys associated with the original two private keys.

This sounds confusing, but the implication is simple: Alice and Carol, when CoinJoining, can add their private signature and emit only the amount that everyone can verify for the total number of public keys. their declaration. Since as we said, the signature is the heaviest part of the online heaviest deal, the ability to broadcast just one instead of many will save a lot of resources. Outside observers will eventually suspect every transaction to be CoinJoin, as many users can after gaining efficiency. This assumption will break most of the legal solutions.

Even without further improvement, the UTXO model somehow increased the scale: Unlike a state change in the account model, it allows validation to be processed in batches and in parallel effectively.