The Japanese Ministry of Economy, Trade, and Industry regards the process of incorporating new information technology, such as artificial intelligence (AI), Internet of Things (IoT), and big data analysis into society as the Fourth Industrial Revolution. This view is reflected in the Fifth Science and Technology Basic Plan. The plan advocates Society 5.0, in which cyber space and physical space are integrated to support an affluent and human-friendly society. Computer scientists regard the interconnection of industry and society through information technologies, with people creating and using such technologies, as a single ecosystem. They have actively participated in the design and discussion of such an integrated ecosystem. Blockchain is considered to be at the core of such a cyber ecosystem.

Terms like the Fourth Industrial Revolution, Society 5.0, and cyber ecosystems seem colorful and might appear rather farfetched. However, when placed in the context of the current states of the economy and technological development, one realizes that the new concepts are rather persuasive. This is because the technological innovation that is about to start is very unique in the long history of technological advancement since the First Industrial Revolution.

Today, we are witnessing the introduction of a new type of productive resource into our economy—data. Data is a new productive resource that had no economic value in the past. Until a few years ago, there was no way to gather large volumes of data that could capture daily life accurately, nor were there any computing technologies that made it possible to analyze an extremely large volume of data to explain complicated human interactions on both production and consumption sides of an economy. This has changed all of a sudden. Many productive resources, such as coal and oil, suddenly became valuable during past industrial revolutions. However, they merely replaced already existing resources. Coal replaced firewood and charcoal; oil replaced coal. Data, in contrast, does not replace any existing resources but is born as a completely new type of productive resource.

In short, industrial revolution in the past meant destroying existing resources and replacing them with new resources. Sitting in the middle of the Fourth Industrial Revolution, in contrast, data does not replace any existing resources.

From an economic viewpoint, this difference between past industrial revolutions and the Fourth Industrial Revolution is large. Previously, the ownership of oil was assigned to the owner of the land containing the oil, just as the ownership of coal was assigned before oil was utilized as a major energy source. In the case of data, we have not established a clear agreement on who owns the data. As Nobel laureate Ronald Coase (1910–2013) pointed out, the assignment of proper ownership rights is a prerequisite for the formation of a market.

In these circumstances, blockchain technology opens important avenues to make efficient and fair use of data. In a broader sense, this technology is also referred to as a “decentralized ledger,” which can involve a large number of unspecified people to contribute to the effective and fair use of data in a decentralized manner.

In summary, blockchain is expected to play an important role in connecting information technology and technologies such as AI, IoT, and big data with our lives. From this point of view, this book investigates the roles that blockchain plays in a virtual ecosystem from various angles, in particular, from the following three viewpoints: (1) data ownership, (2) data transactions, and (3) data industry.

1 Data: A New Productive Resource

If you are a smart phone user, it must be impossible to think of a day without access to the Internet. A mechanism to assign unique numbers to various things and integrate them into the Internet is called the Internet of Things (IoT). Smartphones are all recognized as IoT terminals, identified by their unique identifiers called telephone numbers, and, now, play a central role in data storage on the Internet.

With the exception of the phone function, almost all the information acquired through smartphones is provided through the Internet. At the same time, we have become an important source of information. Buying goods through Amazon is like offering part of your household account book. When using Facebook and the “like” function is used, some sort of preference is expressed toward society. Sending emails also implies providing information to society.

It is not only humans that can be connected with cyber space through IoT. Computer sensors can be placed on livestock in pasture to keep track of their health and nutritional needs. If sensors are attached to trees and every square meter of farmland, the growth conditions of trees and vegetables in every square meter of the field can be monitored. In this way, a new ecosystem of human beings and living things, with information technology as infrastructure, can be created. Sensors on a car can keep track of driving habits, which is useful to enhance driving safety. Similarly, sensors in a hospital room can monitor and report the state of each patient and give useful information to carers. In this way, we can create a new ecosystem based on information and communication technology.

In the ecosystem, all information is digitized and recorded as numbers. This is why the information exchanged in IoT is called data. With modern computer technology, huge volumes of data can be collected and scientifically analyzed in detail to gain insights into various phenomena much deeper and clearer than possible only 10 years ago. Results from data analysis have started to profoundly influence our society.

This has transformed data into a new type of productive resource, by which we can manage production processes in a much more precise manner. With data on people’s medical histories, doctors will be able to diagnose a patient’s illness much more accurately and give better or more appropriate treatments. With data on car driving, insurance companies will evaluate driving risks much more accurately, thus allowing them to reduce insurance fees where appropriate. With data on purchases in stores, both manufacturers and retailers have increased ability to market attractive products to customers. All these possibilities are brought about by the data-gathering capability of the Internet and the data-processing capabilities of modern computers.

2 Blockchain Technology

Blockchain may still be a new term for many readers. It is, therefore, appropriate to start with a discussion on the definition of blockchain.

A ledger is a book of permanent record. The record must be correct and tamper-free. A blockchain is a ledger that is put together on the Internet in a decentralized manner by an indefinite number of contributors.

Blockchain is a chain of files containing whatever needs to be permanently recorded. A basic blockchain connects files to form a simple string of chain. A more sophisticated blockchain connects files to form a net-like structure.

2.1 Blockchain and Data Ownership

A database is like an address book in which many data elements are stored systematically and organized for easy use. Blockchain is a new technology that allows us to record data and sources and recipients of data exchanged on the Internet, thereby creating an accurate, permanent, and very inexpensive database.

The first application of blockchain technology was the virtual currency called Bitcoin. Functionally, a virtual currency is much the same as a deposit currency that is based on bank accounts. Each bank account records debits to and credits from other accounts, which the bank keeps to be absolutely accurate and tamper-free. Because the record shows who owes how much to whom, and because people trust that the records are absolutely reliable, it can be used to transfer money through wire transfers; debit cards are a major means of payment nowadays. A virtual currency is a similar collection of accounts (called wallets) that record debits and credits. The difference is that the virtual currency accounts are on the Internet. Blockchain technology has made it possible to keep this record absolutely reliable by using algorithm without relying on a central authority like a bank.

Blockchain accounts record digital data, which plays the role of money because people trust that they are accurate and tamper-free. As this shows, blockchain can assign the ownership of each data piece to an account holder. This is the innovation that blockchain technology has brought to society.

2.2 Distributed Computing

Distributed computing is a revolutionary innovation in computer networks, which allows many terminal computers to perform complicated tasks independently (Holohan and Garg 2005). One good example is a category of games called “massively multiplayer online games” in which many different players participate and try to achieve their respective goals, which may vary from car racing to shooting to role playing. Blockchain technology is built on this idea of distributed computing and adds decentralization to enable individual participants to maintain a secure record of transactions, ownerships, and promises.

The initial design of a computer network, which connects many computers to share resources, is centrally managed. In building a centralized network, a network administrator is chosen, a large server computer is set up, a network connecting many computers is designed, and software is installed on the server and made available for network users. The administrator centrally manages users’ network connections, and only users with connection permission can use the network. The networks of companies and universities are designed in this way, and the same is true for online banking systems that connect automatic teller machines (ATMs). In a centrally managed network, the terminal computers perform very minimal tasks. For example, a bank ATM terminal recognizes the account number and the password, and then performs simple tasks such as deposits and withdrawals.

As a network becomes larger, it becomes more and more difficult to maintain a centralized network. The load on the central server increases, and the cost of managing the server becomes very large. Central servers can also become very attractive targets for malicious attacks, and once these servers are compromised, the entire system can be destroyed.

A distributed network is built by connecting various independent servers and computers. Various tasks are distributed to different servers, and altogether a single goal can be achieved. A large volume of tasks are assigned to terminal computers. As long as basic rules for connecting to the network are set and those rules are followed, any server and any computer can join the network.

Such rules are called protocols. In the most immediate example, the email address is separated by the at-mark, @; the part after the “at mark” is an address indicating a particular computer group; the part before is an individual in that group. This rule is a very small part of the large Internet protocol.

A distributed network makes it possible to utilize a large portion of the computing power of the computers in a network. The various computers connected to the network perform large tasks by computing independently while coordinating tasks through exchange of data. Having a large number of computers work independently can achieve great goals at very low cost.

2.3 Blockchain: Decentralized Ledger

Distributed computing has evolved as a computer network construction method. Blockchain is a technology that builds a ledger based on distributed computing in a decentralized manner. This might sound simple, but, in reality, it is not. To create a decentralized ledger, it is necessary to devise a totally new algorithm, and such work led to the creation of Bitcoin.

To create and maintain a secure decentralized ledger, it is not enough to use a security program; such security measures can be easily breached by experienced hackers. Even if many independent computers maintain ledger together with good intentions, they are still vulnerable to attacks by computers with malicious intentions. This is especially so if such a ledger maintains records that function as money or virtual currency, where absolute accuracy and permanence are required.

This problem was overcome by the first blockchain, known as Bitcoin. In most blockchain, the database is shared by a large number of servers. Each server stores the entire blockchain record and carries out similar jobs in parallel. These servers are called full nodes of a blockchain. A new server that wants to join a blockchain network is free to copy the blockchain record and download the necessary software to store the records. Once in a while, the records on participating servers are synchronized so that only one record is produced. With more nodes, the number of copies of the blockchain’s ledger throughout the world increases, which makes it extremely difficult for malicious computers to attack the blockchain.

The decentralized ledger database is linked with user accounts called wallets. A wallet is a record of a particular user’s transactions, which is kept on the user’s terminal computer. Once a transaction between two accounts is agreed upon, the account owners apply to the blockchain to record the transaction. In most of the existing blockchains, recorders of transactions are different from users who use a blockchain as a currency. In some blockchains, users of a blockchain record their transactions by themselves.

2.4 Mining

The Bitcoin blockchain uses “mining” to maintain the accuracy and reliability of transaction records.Footnote 1 Mining in the context of blockchain technology is to present a computer-generated crypto puzzle to individuals (computers), to give a prize (in Bitcoin) to the individual who solves the puzzle first, and to let the individual record the transaction. In competing for the prize, many people (computers) engage in solving the crypto puzzle to create transaction records. With only one individual out of many competitors receiving the prize, this process is similar to mining; and individuals engaging in solving puzzles are called miners.

As soon as a mining computer solves the existing puzzle, a new file (block) is created and attached to the existing chain of blocks. The new block creates a new puzzle to be solved. At the same time, the solution is announced to the network of mining computers. Mining computers check if that solution is correct. If the solution is in fact correct, mining computers start working on solving the new puzzle created by the block that they have just validated.

In this entire process, it is important that there is no single individual who is in charge of checking the validity and uniqueness of records on blockchain. Instead, many independent individuals check the validity of records, which produces a unique record (ledger). This process is completely decentralized.

For Bitcoin blockchain, on one hand, simple records of several transactions are put together and recorded as a new block. On the other hand, for Ethereum blockchain, user-executable computer programs and resulting transactions of executing the programs can be written into a new block by a mining node.

A problem with blockchains is that mining consumes computer resources not directly related to records. Many miners work on solving the puzzle posed by the blockchain. Because this puzzle can be solved by a sequence of computations, anyone can find an answer so long as he/she is prepared to spend enough computing resources.

As a result, if there are 1,000 miners, the computational resources used by 999 miners (i.e., electricity to run computations) will be wasted. As the value of virtual currency soars, the number of miners has increased dramatically, and it is said that about 10,000 miners are active around the world. Given that the average time required to solve the puzzle is 10 min, it is possible that a huge amount of electricity is being wasted. To maintain the accuracy of the blockchain, a certain number of miners must be involved. Whether electricity is wasted is related to the number of miners required to maintain accuracy.

2.5 Advancement of Blockchain Technology

The Bitcoin blockchain proved that a secure ledger can be created in a decentralized manner without using a trusted authority who is specialized in managing a ledger. Since then, different types of blockchains have been created.

A blockchain called IOTA creates a blockchain model that is not based on mining, hence does not consume a large amount of electricity. The IOTA blockchain is not a linear chain of files as used by the Bitcoin blockchain. Instead, it has a very complicated network structure, which itself is impossible to replicate. This structure is called a directed acyclic graph (DAG). Each transaction file (block) is given two arms, each of which randomly grabs another file (directed from grabbing to grabbed files). As the number of files becomes larger, the number of arms increases by the power of 2, which soon becomes an extremely complicated structure. In this structure, a sequence of files is created in which a particular file grabs another file, which will grab the next, and so on. It has been shown that if such a sequence never contains a circle (acyclic), the structure can serve as a blockchain, which can dispense with the requirement for mining.

A few years after Bitcoin was introduced, a new blockchain called Ethereum was developed. It was able to execute any program and to create execution records, as well as record transactions.

Not only does Ethereum provide its own virtual currency, called Ether, it also works in conjunction with Ether to provide a “platform” for loading and executing programs. These programs are called smart contracts, which can program the execution of a promise between users with various contingencies.

Once a business can be run on a blockchain, business developers seek funding to further develop the business or for future businesses. Such funding is also carried out over the Internet in a manner similar to crowd funding. This method of funding is called ICO (initial coin offering), and it sells and collects funds for business vouchers called tokens.

3 Building a People-Friendly Ecosystem

Information technologies such as AI, IoT, and big data are expected to contribute greatly to the realization of a new human-friendly ecosystem. However, it is a mistake to think that such an ecosystem will be built if technological innovation is realized. The modern economy faces major problems of data monopoly and data abuse. Society 5.0 can be formed only after overcoming these problems.

3.1 Society 5.0

The blueprint of Society 5.0 as advocated by the Japanese government is based on the following loop: collection of data from every part of society by IoT, creation of big data, data analysis by AI, and injection of results of data analysis back to society.

The government states, “In the information society (Society 4.0), cross-sectional sharing of knowledge and information was not enough, and cooperation was difficult.”Footnote 2 It continues, “Social reform (innovation) in Society 5.0 will achieve a forward-looking society that breaks down the existing sense of stagnation, a society whose members have mutual respect for each other, transcending the generations, and a society in which each and every person can lead an active and enjoyable life.”

The government argues, “Society 5.0 achieves a high degree of convergence between cyberspace (virtual space) and physical space (real space)…In the past information society, the common practice was to collect information via the network and have it analyzed by humans. In Society 5.0, however, people, things, and systems are all connected in cyberspace and optimal results obtained by AI exceeding the capabilities of humans are fed back to physical space. This process brings new value to industry and society in ways not previously possible.” However, it is a mistake to assume that so long as technological innovation progresses, the image of Society 5.0 will naturally be realized without any effort.

3.2 Industrial Revolution and Market Quality

Since the First Industrial Revolution, industrialization has brought about the concentration of resources in specific industries and companies. Yano (2009) views this process as a dynamical system of technology and market quality.Footnote 3 According to Yano, massive technological progress lowers market quality. This brings about various social problems; essentially, the concentration of resources causes fundamental changes in lifestyle and social structure. Once market quality falls to a certain level, however, demand will increase because of accumulated knowledge and experience, which will stimulate new innovation (Yano and Furukawa 2019).

The First Industrial Revolution (1760s to the 1840s) began with the invention of steam engines in England. The textile industry underwent major technological innovation, many workers were hired, capital was invested, and production expanded. Instead of engaging in in-house production activities, people were hired in large factories. Capital was accumulated by companies rather than by individuals. This resulted in the exploitation of workers, which Karl Marx (1818–1883) criticized harshly (Marx 1867). The Second Industrial Revolution came with steel production, railways, large-scale iron and steel production, electricity, telegraphs and telephones, and machinery. Major companies became enormous, and were perceived as a menace to society (Hilferding 1910).

3.3 Data Monopoly and Data Abuse

Yano’s theory applies to the recent progress brought about by the technological revolution in information and communication technology (ICT revolution). One of the most successful groups of companies after the turn of the century is GAFA, which represents the initials of Google, Amazon, Facebook, and Apple. These companies were very successful during the ICT revolution, and, in doing so, have collected large volumes of data.

This concentration of resources realized economies of scale and production efficiency. Nevertheless, many people are worried about data concentration on GAFA (Radingsky 2015).

This worry is not imaginary but real, as shown by the recent abuse of data collection by Cambridge Analytica. Cambridge Analytica is alleged to have collected the personal data of 230 million Americans through Facebook accounts and used it to influence voters in favor of Donald Trump in the 2016 US presidential election (Cadwalladr 2018).The original method of data collection, which was developed by two psychologists, was to offer an Internet-based psychological test for anyone interested, and, at the end of the test seek permission to access the respondent’s Facebook profile. According to Cadwalladr (2018), 40% of the respondents gave permission. By using the data, the psychologists were able to measure personality traits and to correlate scores against Facebook “likes” for millions of people. This method was adopted by Cambridge Analytica, which obtained personal data and then devised methods to influence important votes such as the US presidential election and the Brexit referendum.

This is a clear warning that data can be badly abused by monopolizing it. Unless these problems are resolved, the integration of cyber and physical spaces may end up with a rather dark society that is far from the image presented by the Society 5.0 initiative. Avoiding the emergence of such a dark society is a pressing issue that we now face (Economist 2018).

3.4 Small to Medium-Sized Enterprises

Many people say that in the digital economy, data is a production factor equivalent to oil. Data needs to be shared and distributed throughout society if it is to be used effectively in the digital age. So far, however, data has accumulated in the hands of large companies trying to establish competitive advantage. As a result, data is just stored, and it is becoming more difficult for small and medium-sized companies to use data for innovation.

For small to medium-sized enterprises, an even bigger problem is that they do not have good access to human resources specialized in handling data. This has created an egg-or-chicken paradox. To break such a vicious cycle, we require a good ecosystem that allows everyone to own and trade data and utilize the results of data analysis.

To resolve these problems, blockchain technology is ideal. It can be expected to release data to every productive sector, thereby enhancing the productivity of the economy as a whole.

4 Organization of This Book

As discussed above, the integration of cyber space and physical space will not automatically lead to the creation of a human-friendly society unless a sound interface is created between such a society and data as a new economic resource. The main purpose of this book is to investigate the role of blockchains as such an interface. In particular, we focus on the roles of blockchains from three viewpoints: (1) data ownership, (2) data transactions, and (3) the data industry.

4.1 Data Ownership

Many people think that as the IoT becomes more important in the production process, data will become an increasingly important production factor. To make good use of these new resources, it is necessary to start with setting ownership. In Chapter 2, Steven Pu and Makoto Yano cover this issue in the context of market quality theory.

As pointed out by Ronald Coase, a resource cannot be put on a market unless proper ownership is assigned to the resource. Many people say that data in a coming digital economy is a production factor equivalent to oil for the existing economy.

To whom should ownership be assigned for such an important production factor? It is our view that the ownership of data should belong to the originator of data so as to avoid inefficient and unfair use of data, which may result from monopoly and abuse of data.

Currently, most data that we produce is collected and accumulated by large Internet data companies, as presented by GAFA. Such data is kept in a black box, and there is no way for ordinary people to know how it is used. For the oil industry, on the one hand, everyone has a relatively clear understanding on the supply chain from producers to consumers. In the case of data, on the other hand, how it is used is kept under a veil.

For data to play an equally important role as oil in digital society, it must be shared and used by many people. Nevertheless, an increasing number of large companies are monopolizing data to establish a competitive advantage. Being stored in large companies, it is becoming increasingly difficult for small and medium-sized companies to use data for innovation. On the other hand, for large companies, there is no strong incentive to use data; it is adequate to hold the information to deter challenges from competitors. How can we improve this situation?

The first step is to return ownership of the data to the individual who produces it. Blockchains make it possible to record data ownership at a low cost. Once the ownership of data is decided, data can be traded. To assign proper ownership of IoT data and put it on a market, it is necessary to develop a new blockchain technology. In Chapter 3, Steven Pu explains the development of this technology.

4.2 Data as Money

As an increasing number of people accept Bitcoin and other virtual currencies, a number of associated problems have arisen, such as money laundering, transactions of illegal drugs, and speculative activities. If these problems are not resolved, virtual currencies may not circulate widely. At the same time, however, blockchain technology itself has shown that data can be used as money. It can create a reliable record (ledger) of transactions in a decentralized manner without a central administrator. In Chapter 4, Makoto Yano investigates the possibility that such a decentralized ledger currency can take over the conventional deposit currency and paper money, once the existing problems are overcome.

4.3 Data Industry

As noted above, Ethereum is a technology that makes it possible to run any program and to record the results on blockchain. This opens up an infinitely large possibility for blockchain business.

The market in which data is traded on blockchain is often called a marketplace. In a marketplace, anything can be traded from candy to golf club memberships. These transactions are made by software applications called decentralized applications (DApps). In Chapter 5, William Metcalfe explains the role of smart contracts in Ethereum and the current state of DApp technology and their applications.

In a blockchain marketplace, all transaction records are made public. In exchanges for virtual currencies, in contrast, they are not made public; in this respect, they are similar to marketplaces such as Amazon. For this reason, a virtual currency exchange can be called a centralized marketplace. Centralized marketplaces present themselves as a single point of failure, and, therefore, are prone to malicious attacks. Moreover, they lack transparency such that the actions of the organizer of a centralized market cannot be monitored by outsiders.

A bottleneck of the current virtual currency system is the time needed to carry out transactions. To overcome this problem and to provide more convenient transactions, an exchange market for virtual currency has been developed. However, the existing virtual currency exchanges are centrally controlled by exchange organizers. As a result, they are prone to malicious attacks, and in fact, a number of hacking incidents on exchange has been reported.Footnote 4

The decentralized exchange (DEX) is a new DApp that has been developed to cope with this weak points of centralized marketplaces. DEX allows a seller and a buyer of crypto assets to make a direct exchange in a decentralized manner on blockchain. Data (crypto assets and transaction records) is held in a decentralized manner so that DEX does not present itself as a single point of failure to attackers. Furthermore, because the system is open to the public, transactions can be made in a much more transparent fashion. It is offered in exchange for investments in DApp development. In Chapter 6, Chris Dai explains DApps and DEX and explains the current state of token business.

A token is a device to raise funds for developing blockchains and blockchain applications (DApps). A token can be thought of as a ticket for using the services that a DApp promises to offer. It is offered in exchange for investments in DApp development.

The introduction of fundraising by token issuance may be a result of the decentralized nature of blockchain technologies. Because of decentralization, the start-up process of blockchain businesses is significantly different from that of conventional businesses. In the current state of society, in which blockchains are not yet established, it may be desirable to treat start-up blockchain businesses like venture investments. However, once the technology is established, a new decentralized financial system will become necessary. From these perspectives, in Chapter 7, we consider the desirable designs for a decentralized financial system for both short-term and long-term scenarios.

The main message of this study is that it is important to build an ecosystem in which the new technology (blockchain), laws and institutions, including data ownership, and markets for digital assets are harmonized. Market quality theory suggests that the ownership of big data collected through the Internet should be assigned in such a way to support high-quality digital data markets. See Chapters 2 and 7 for a discussion on desirable designs of the decentralized financial system from these perspectives.

In Chapter 8, Kazumasa Omote and Makoto Yano discuss the blockchain technology on which Bitcoin is based.