Blockchain

A blockchain is a distributed ledger with growing lists of records (blocks) that are securely linked together via cryptographic hashes.[1][2][3][4] Each block contains a cryptographic hash of the previous block, a timestamp, and transaction data (generally represented as a Merkle tree, where data nodes are represented by leaves). Since each block contains information about the previous block, they effectively form a chain (compare linked list data structure), with each additional block linking to the ones before it. Consequently, blockchain transactions are resistant to alteration because, once recorded, the data in any given block cannot be changed retroactively without altering all subsequent blocks and obtaining network consensus to accept these changes.

Blockchains are typically managed by a peer-to-peer (P2P) computer network for use as a public distributed ledger, where nodes collectively adhere to a consensus algorithm protocol to add and validate new transaction blocks. Although blockchain records are not unalterable, since blockchain forks are possible, blockchains may be considered secure by design and exemplify a distributed computing system with high Byzantine fault tolerance.[5]

A blockchain was created by a person (or group of people) using the name (or pseudonym) Satoshi Nakamoto in 2008 to serve as the public distributed ledger for bitcoin cryptocurrency transactions, based on previous work by Stuart Haber, W. Scott Stornetta, and Dave Bayer.[6] The implementation of the blockchain within bitcoin made it the first digital currency to solve the double-spending problem without the need for a trusted authority or central server. The bitcoin design has inspired other applications[3][2] and blockchains that are readable by the public and are widely used by cryptocurrencies. The blockchain may be considered a type of payment rail.[7]

Private blockchains have been proposed for business use. Computerworld called the marketing of such privatized blockchains without a proper security model "snake oil";[8] however, others have argued that permissioned blockchains, if carefully designed, may be more decentralized and therefore more secure in practice than permissionless ones.[4][9]

## Contents

* 1 History
* 2 Structure and design
* 2.1 Blocks
* 2.1.1 Block time
* 2.1.2 Hard forks
* 2.2 Decentralization
* 2.2.1 Finality
* 2.3 Openness
* 2.3.1 Permissionless (public) blockchain
* 2.3.2 Permissioned (private) blockchain
* 2.3.2.1 Disadvantages of permissioned blockchain
* 2.3.3 Blockchain analysis
* 2.4 Standardisation
* 2.5 Centralized blockchain
* 3 Types
* 3.1 Public blockchains
* 3.2 Private blockchains
* 3.3 Hybrid blockchains
* 3.4 Sidechains
* 3.5 Consortium blockchain
* 4 Uses
* 5 Cryptocurrencies
* 5.1 Smart contracts
* 5.2 Financial services
* 5.3 Games
* 5.4 Supply chain
* 5.5 Domain names
* 5.6 Other uses
* 6 Blockchain interoperability
* 7 Energy consumption concerns
* 8 Academic research
* 8.1 Adoption decision
* 8.2 Collaboration
* 8.3 Blockchain and internal audit
* 8.4 Testnet
* 8.5 Mainnet
* 8.6 Journals
* 9 See also
* 10 References
* 11 Further reading
* 12 External links

## History

Cryptographer David Chaum first proposed a blockchain-like protocol in his 1982 dissertation "Computer Systems Established, Maintained, and Trusted by Mutually Suspicious Groups".[10][11] Further work on a cryptographically secured chain of blocks was described in 1991 by Stuart Haber and W. Scott Stornetta.[4][12] They wanted to implement a system wherein document timestamps could not be tampered with. In 1992, Haber, Stornetta, and Dave Bayer incorporated Merkle trees into the design, which improved its efficiency by allowing several document certificates to be collected into one block.[4][13] Under their company Surety, their document certificate hashes have been published in The New York Times every week since 1995.[14]

The first decentralized blockchain was conceptualized by a person (or group of people) known as Satoshi Nakamoto in 2008. Nakamoto improved the design in an important way using a Hashcash-like method to timestamp blocks without requiring them to be signed by a trusted party and introducing a difficulty parameter to stabilize the rate at which blocks are added to the chain.[4] The design was implemented the following year by Nakamoto as a core component of the cryptocurrency bitcoin, where it serves as the public ledger for all transactions on the network.[3]

In August 2014, the bitcoin blockchain file size, containing records of all transactions that have occurred on the network, reached 20 GB (gigabytes).[15] In January 2015, the size had grown to almost 30 GB, and from January 2016 to January 2017, the bitcoin blockchain grew from 50 GB to 100 GB in size. The ledger size had exceeded 200 GB by early 2020.[16]

The words block and chain were used separately in Satoshi Nakamoto's original paper, but were eventually popularized as a single word, blockchain, by 2016.[17]

According to Accenture, an application of the diffusion of innovations theory suggests that blockchains attained a 13.5% adoption rate within financial services in 2016, therefore reaching the early adopters' phase.[18] Industry trade groups joined to create the Global Blockchain Forum in 2016, an initiative of the Chamber of Digital Commerce.

In May 2018, Gartner found that only 1% of CIOs indicated any kind of blockchain adoption within their organisations, and only 8% of CIOs were in the short-term "planning or [looking at] active experimentation with blockchain".[19] For the year 2019 Gartner reported 5% of CIOs believed blockchain technology was a 'game-changer' for their business.[20]

## Structure and design

Blockchain formation. The main chain (black) consists of the longest series of blocks from the genesis block (green) to the current block. Orphan blocks (purple) exist outside of the main chain.

A blockchain is a decentralized, distributed, and often public, digital ledger consisting of records called blocks that are used to record transactions across many computers so that any involved block cannot be altered retroactively, without the alteration of all subsequent blocks.[3][21] This allows the participants to verify and audit transactions independently and relatively inexpensively.[22] A blockchain database is managed autonomously using a peer-to-peer network and a distributed timestamping server. They are authenticated by mass collaboration powered by collective self-interests.[23] Such a design facilitates robust workflow where participants' uncertainty regarding data security is marginal. The use of a blockchain removes the characteristic of infinite reproducibility from a digital asset. It confirms that each unit of value was transferred only once, solving the long-standing problem of double-spending. A blockchain has been described as a value-exchange protocol.[24]

Logically, a blockchain can be seen as consisting of several layers:[25]

* infrastructure (hardware)
* networking (node discovery, information propagation[26] and verification)
* consensus (proof of work, proof of stake)
* data (blocks, transactions)
* application (smart contracts/decentralized applications, if applicable)

### Blocks

Blocks hold batches of valid transactions that are hashed and encoded into a Merkle tree.[3] Each block includes the cryptographic hash of the prior block in the blockchain, linking the two. The linked blocks form a chain.[3] This iterative process confirms the integrity of the previous block, all the way back to the initial block, which is known as the genesis block (Block 0).[27] To assure the integrity of a block and the data contained in it, the block is usually digitally signed.[28]

Sometimes separate blocks can be produced concurrently, creating a temporary fork. In addition to a secure hash-based history, any blockchain has a specified algorithm for scoring different versions of the history so that one with a higher score can be selected over others. Blocks not selected for inclusion in the chain are called orphan blocks.[27] Peers supporting the database have different versions of the history from time to time. They keep only the highest-scoring version of the database known to them. Whenever a peer receives a higher-scoring version (usually the old version with a single new block added) they extend or overwrite their own database and retransmit the improvement to their peers. There is never an absolute guarantee that any particular entry will remain in the best version of history forever. Blockchains are typically built to add the score of new blocks onto old blocks and are given incentives to extend with new blocks rather than overwrite old blocks. Therefore, the probability of an entry becoming superseded decreases exponentially[29] as more blocks are built on top of it, eventually becoming very low.[3][30]: ch. 08 [31] For example, bitcoin uses a proof-of-work system, where the chain with the most cumulative proof-of-work is considered the valid one by the network. There are a number of methods that can be used to demonstrate a sufficient level of computation. Within a blockchain the computation is carried out redundantly rather than in the traditional segregated and parallel manner.[32]

#### Block time

The block time is the average time it takes for the network to generate one extra block in the blockchain. By the time of block completion, the included data becomes verifiable. In cryptocurrency, this is practically when the transaction takes place, so a shorter block time means faster transactions. The block time for Ethereum is set to between 14 and 15 seconds, while for bitcoin it is on average 10 minutes.[33]

#### Hard forks

This section is an excerpt from Fork (blockchain) § Hard fork[ edit ]

A hard fork is a change to the blockchain protocol that is not backward compatible and requires all users to upgrade their software in order to continue participating in the network. In a hard fork, the network splits into two separate versions: one that follows the new rules and one that follows the old rules.

For example, Ethereum was hard forked in 2016 to "make whole" the investors in The DAO, which had been hacked by exploiting a vulnerability in its code. In this case, the fork resulted in a split creating Ethereum and Ethereum Classic chains. In 2014 the Nxt community was asked to consider a hard fork that would have led to a rollback of the blockchain records to mitigate the effects of a theft of 50 million NXT from a major cryptocurrency exchange. The hard fork proposal was rejected, and some of the funds were recovered after negotiations and ransom payment. Alternatively, to prevent a permanent split, a majority of nodes using the new software may return to the old rules, as was the case of bitcoin split on 12 March 2013.[34]

A more recent hard-fork example is of Bitcoin in 2017, which resulted in a split creating Bitcoin Cash.[35] The network split was mainly due to a disagreement in how to increase the transactions per second to accommodate for demand.[36]

### Decentralization

By storing data across its peer-to-peer network, the blockchain eliminates some risks that come with data being held centrally.[3] The decentralized blockchain may use ad hoc message passing and distributed networking.[37]

In a so-called "51% attack" a central entity gains control of more than half of a network and can then manipulate that specific blockchain record at will, allowing double-spending.[38]

Blockchain security methods include the use of public-key cryptography.[39]: 5 A public key (a long, random-looking string of numbers) is an address on the blockchain. Value tokens sent across the network are recorded as belonging to that address. A private key is like a password that gives its owner access to their digital assets or the means to otherwise interact with the various capabilities that blockchains now support. Data stored on the blockchain is generally considered incorruptible.[3]

Every node in a decentralized system has a copy of the blockchain. Data quality is maintained by massive database replication[40] and computational trust. No centralized "official" copy exists and no user is "trusted" more than any other.[39] Transactions are broadcast to the network using the software. Messages are delivered on a best-effort basis. Early blockchains rely on energy-intensive mining nodes to validate transactions,[27] add them to the block they are building, and then broadcast the completed block to other nodes.[30]: ch. 08 Blockchains use various time-stamping schemes, such as proof-of-work, to serialize changes.[41] Later consensus methods include proof of stake.[27] The growth of a decentralized blockchain is accompanied by the risk of centralization because the computer resources required to process larger amounts of data become more expensive.[42]

#### Finality

Finality is the level of confidence that the well-formed block recently appended to the blockchain will not be revoked in the future (is "finalized") and thus can be trusted. Most distributed blockchain protocols, whether proof of work or proof of stake, cannot guarantee the finality of a freshly committed block, and instead rely on "probabilistic finality": as the block goes deeper into a blockchain, it is less likely to be altered or reverted by a newly found consensus.[43]

Byzantine fault tolerance-based proof-of-stake protocols purport to provide so called "absolute finality": a randomly chosen validator proposes a block, the rest of validators vote on it, and, if a supermajority decision approves it, the block is irreversibly committed into the blockchain.[43] A modification of this method, an "economic finality", is used in practical protocols, like the Casper protocol used in Ethereum: validators which sign two different blocks at the same position in the blockchain are subject to "slashing", where their leveraged stake is forfeited.[43]

### Openness

Open blockchains are more user-friendly than some traditional ownership records, which, while open to the public, still require physical access to view. Because all early blockchains were permissionless, controversy has arisen over the blockchain definition. An issue in this ongoing debate is whether a private system with verifiers tasked and authorized (permissioned) by a central authority should be considered a blockchain.[44][45][46][47][48] Proponents of permissioned or private chains argue that the term "blockchain" may be applied to any data structure that batches data into time-stamped blocks. These blockchains serve as a distributed version of [[multiversion concurrency control (MVCC) in databases.[49] Just as MVCC prevents two transactions from concurrently modifying a single object in a database, blockchains prevent two transactions from spending the same single output in a blockchain.[50]: 30–31 Opponents say that permissioned systems resemble traditional corporate databases, not supporting decentralized data verification, and that such systems are not hardened against operator tampering and revision.[44][46] Nikolai Hampton of Computerworld said that "many in-house blockchain solutions will be nothing more than cumbersome databases," and "without a clear security model, proprietary blockchains should be eyed with suspicion."[8][51]

#### Permissionless (public) blockchain

An advantage to an open, permissionless, or public, blockchain network is that guarding against bad actors is not required and no access control is needed.[29] This means that applications can be added to the network without the approval or trust of others, using the blockchain as a transport layer.[29]

Bitcoin and other cryptocurrencies currently secure their blockchain by requiring new entries to include proof of work. To prolong the blockchain, bitcoin uses Hashcash puzzles. While Hashcash was designed in 1997 by Adam Back, the original idea was first proposed by Cynthia Dwork and Moni Naor and Eli Ponyatovski in their 1992 paper "Pricing via Processing or Combatting Junk Mail".

In 2016, venture capital investment for blockchain-related projects was weakening in the US but increasing in China.[52] Bitcoin and many other cryptocurrencies use open (public) blockchains. As of April 2018[update], bitcoin has the highest market capitalization.

#### Permissioned (private) blockchain

See also: Distributed ledger

Permissioned blockchains use an access control layer to govern who has access to the network.[53] It has been argued that permissioned blockchains can guarantee a certain level of decentralization, if carefully designed, as opposed to permissionless blockchains, which are often centralized in practice.[9]

##### Disadvantages of permissioned blockchain

Nikolai Hampton argued in Computerworld that "There is also no need for a '51 percent' attack on a private blockchain, as the private blockchain (most likely) already controls 100 percent of all block creation resources. If you could attack or damage the blockchain creation tools on a private corporate server, you could effectively control 100 percent of their network and alter transactions however you wished."[8] This has a set of particularly profound adverse implications during a financial crisis or debt crisis such as the 2008 financial crisis, where politically powerful actors may make decisions that favor some groups at the expense of others,[54] and "the bitcoin blockchain is protected by the massive group mining effort. It's unlikely that any private blockchain will try to protect records using gigawatts of computing power — it's time-consuming and expensive."[8] He also said, "Within a private blockchain there is also no 'race'; there's no incentive to use more power or discover blocks faster than competitors. This means that many in-house blockchain solutions will be nothing more than cumbersome databases."[8]

#### Blockchain analysis

The analysis of public blockchains has become increasingly important with the popularity of bitcoin, Ethereum, litecoin and other cryptocurrencies.[55] A blockchain, if it is public, provides access to anyone to observe and analyse the chain data, given the know-how. The process of understanding and accessing the flow of crypto has been an issue for many cryptocurrencies, crypto exchanges and banks.[56][57] The reason for this is accusations of blockchain-enabled cryptocurrencies enabling illicit dark market trading of drugs, weapons, money laundering, etc.[58] A common belief has been that cryptocurrency is private and untraceable, thus leading many actors to use it for illegal purposes. This is changing now that specialised tech companies provide blockchain tracking services, making crypto exchanges, law-enforcement and banks more aware of what is happening with crypto funds and fiat-crypto exchanges. The development, some argue, has led criminals to prioritise the use of new cryptos such as Monero.[59][60][61]

### Standardisation

In April 2016, Standards Australia submitted a proposal to the International Organization for Standardization to consider developing standards to support blockchain technology. This proposal resulted in the creation of ISO Technical Committee 307, Blockchain and Distributed Ledger Technologies.[62] The technical committee has working groups relating to blockchain terminology, reference architecture, security and privacy, identity, smart contracts, governance and interoperability for blockchain and DLT, as well as standards specific to industry sectors and generic government requirements.[63][non-primary source needed] More than 50 countries are participating in the standardization process together with external liaisons such as the Society for Worldwide Interbank Financial Telecommunication (SWIFT), the European Commission, the International Federation of Surveyors, the International Telecommunication Union (ITU) and the United Nations Economic Commission for Europe (UNECE).[63]

Many other national standards bodies and open standards bodies are also working on blockchain standards.[64] These include the National Institute of Standards and Technology[65] (NIST), the European Committee for Electrotechnical Standardization[66] (CENELEC), the Institute of Electrical and Electronics Engineers[67] (IEEE), the Organization for the Advancement of Structured Information Standards (OASIS), and some individual participants in the Internet Engineering Task Force[68] (IETF).

### Centralized blockchain

Although most of blockchain implementation are decentralized and distributed, Oracle launched a centralized blockchain table feature in Oracle 21c database. The Blockchain Table in Oracle 21c database is a centralized blockchain which provide immutable feature. Compared to decentralized blockchains, centralized blockchains normally can provide a higher throughput and lower latency of transactions than consensus-based distributed blockchains.[69][70]

## Types

Currently, there are at least four types of blockchain networks — public blockchains, private blockchains, consortium blockchains and hybrid blockchains.

### Public blockchains

A public blockchain has no access restrictions. Anyone with an Internet connection can send transactions to it as well as become a validator (i.e., participate in the execution of a consensus protocol).[71][self-published source?] Usually, such networks offer economic incentives for those who secure them and utilize some type of a proof-of-stake or proof-of-work algorithm.

Some of the largest, most known public blockchains are the bitcoin blockchain and the Ethereum blockchain.

### Private blockchains

A private blockchain is permissioned.[53] One cannot join it unless invited by the network administrators. Participant and validator access is restricted. To distinguish between open blockchains and other peer-to-peer decentralized database applications that are not open ad-hoc compute clusters, the terminology Distributed Ledger (DLT) is normally used for private blockchains.

### Hybrid blockchains

A hybrid blockchain has a combination of centralized and decentralized features.[72] The exact workings of the chain can vary based on which portions of centralization and decentralization are used.

### Sidechains

A sidechain is a designation for a blockchain ledger that runs in parallel to a primary blockchain.[73][74] Entries from the primary blockchain (where said entries typically represent digital assets) can be linked to and from the sidechain; this allows the sidechain to otherwise operate independently of the primary blockchain (e.g., by using an alternate means of record keeping, alternate consensus algorithm, etc.).[75]

### Consortium blockchain

A consortium blockchain is a type of blockchain that combines elements of both public and private blockchains. In a consortium blockchain, a group of organizations come together to create and operate the blockchain, rather than a single entity. The consortium members jointly manage the blockchain network and are responsible for validating transactions. Consortium blockchains are permissioned, meaning that only certain individuals or organizations are allowed to participate in the network. This allows for greater control over who can access the blockchain and helps to ensure that sensitive information is kept confidential.

Consortium blockchains are commonly used in industries where multiple organizations need to collaborate on a common goal, such as supply chain management or financial services. One advantage of consortium blockchains is that they can be more efficient and scalable than public blockchains, as the number of nodes required to validate transactions is typically smaller. Additionally, consortium blockchains can provide greater security and reliability than private blockchains, as the consortium members work together to maintain the network. Some examples of consortium blockchains include Quorum and Hyperledger.[76]

## Uses

Blockchain technology can be integrated into multiple areas.[77] The primary use of blockchains is as a distributed ledger for cryptocurrencies such as bitcoin; there were also a few other operational products that had matured from proof of concept by late 2016.[52] As of 2016, some businesses have been testing the technology and conducting low-level implementation to gauge blockchain's effects on organizational efficiency in their back office.[78]

Blockchain is seen as a pivotal technological advancement of the 21st century, with the ability to impact organizations at strategic, operational, and market levels.[79] In 2019, it was estimated that around $2.9 billion were invested in blockchain technology, which represents an 89% increase from the year prior. Additionally, the International Data Corp estimated that corporate investment into blockchain technology would reach $12.4 billion by 2022.[80] Furthermore, According to PricewaterhouseCoopers (PwC), the second-largest professional services network in the world, blockchain technology has the potential to generate an annual business value of more than $3 trillion by 2030. PwC's estimate is further augmented by a 2018 study that they have conducted, in which PwC surveyed 600 business executives and determined that 84% have at least some exposure to utilizing blockchain technology, which indicates a significant demand and interest in blockchain technology.[81]

In 2019, the BBC World Service radio and podcast series Fifty Things That Made the Modern Economy identified blockchain as a technology that would have far-reaching consequences for economics and society. The economist and Financial Times journalist and broadcaster Tim Harford discussed why the underlying technology might have much wider applications and the challenges that needed to be overcome.[82] His first broadcast was on 29 June 2019.

The number of blockchain wallets quadrupled to 40 million between 2016 and 2020.[83]

A paper published in 2022 discussed the potential use of blockchain technology in sustainable management.[84]

## Cryptocurrencies

Most cryptocurrencies are designed to gradually decrease the production of that currency, placing a cap on the total amount of that currency that will ever be in circulation.[85] Compared with ordinary currencies held by financial institutions or kept as cash on hand, cryptocurrencies can be more difficult for seizure by law enforcement.[85]

The validity of each cryptocurrency's coins is provided by a blockchain. A blockchain is a continuously growing list of records, called blocks, which are linked and secured using cryptography.[85][86] Each block typically contains a hash pointer as a link to a previous block,[86] a timestamp and transaction data.[87] By design, blockchains are inherently resistant to modification of the data. It is "an open, distributed ledger that can record transactions between two parties efficiently and in a verifiable and permanent way".[86] For use as a distributed ledger, a blockchain is typically managed by a peer-to-peer network collectively adhering to a protocol for validating new blocks. Once recorded, the data in any given block cannot be altered retroactively without the alteration of all subsequent blocks, which requires collusion of the network majority.

Blockchains are secure by design and are an example of a distributed computing system with high Byzantine fault tolerance. Decentralized consensus has therefore been achieved with a blockchain.[88]

In the context of cryptocurrencies, the blockchain serves as a public ledger for all transactions. Cryptocurrencies use various timestamping schemes to "prove the validity of transactions added to the blockchain ledger without the need for a trusted third party".[85]

The first cryptocurrency was Bitcoin, which was first released as open-source software in 2009.

As cryptocurrencies have gained prominence, several countries have made advancements in their private and commercial law treatment to address legal uncertainties. In the United States, for example, the 2022 amendments to the Uniform Commercial Code (UCC) introduced Article 12, which establishes "controllable electronic records" (CERs) as a new category of personal property. This framework provides legal clarity for the ownership, transfer, and use of cryptocurrencies as CERs, with the concept of "control" serving as a functional equivalent to possession for digital assets. These reforms aim to align legal standards with market practices, reducing title disputes and supporting the integration of cryptocurrencies into commercial transactions.[89]

### Smart contracts

Main article: Finance:Smart contract

Blockchain-based smart contracts are contracts that can be partially or fully executed or enforced without human interaction.[90] One of the main objectives of a smart contract is automated escrow. A key feature of smart contracts is that they do not need a trusted third party (such as a trustee) to act as an intermediary between contracting entities — the blockchain network executes the contract on its own. This may reduce friction between entities when transferring value and could subsequently open the door to a higher level of transaction automation.[91] An IMF staff discussion from 2018 reported that smart contracts based on blockchain technology might reduce moral hazards and optimize the use of contracts in general, but "no viable smart contract systems have yet emerged." Due to the lack of widespread use, their legal status was unclear.[92][93]

### Financial services

According to Reason, many banks have expressed interest in implementing distributed ledgers for use in banking and are cooperating with companies creating private blockchains;[94][95][96] according to a September 2016 IBM study, it is occurring faster than expected.[97] It has been estimated by the World Economic Forum that by 2025, 10% of the world's GDP will be stored on blockchain related technology.[79]

Banks are interested in this technology not least because it has the potential to speed up back office settlement systems.[98] Moreover, as the blockchain industry has reached early maturity institutional appreciation has grown that it is, practically speaking, the infrastructure of a whole new financial industry, with all the implications which that entails.[99] This technology will transform financial transactions due to its ability to enhance data storage, process simultaneous transactions, lessen transaction costs, and improve capital market transparency for debt and equity capital administration.[79]

Banks such as UBS are opening new research labs dedicated to blockchain technology in order to explore how blockchain can be used in financial services to increase efficiency and reduce costs.[100][101]

Berenberg, a German bank, believes that blockchain is an "overhyped technology" that has had a large number of "proofs of concept", but still has major challenges, and very few success stories.[102]

The blockchain has also given rise to initial coin offerings (ICOs) as well as a new category of digital asset called security token offerings (STOs), also sometimes referred to as digital security offerings (DSOs).[103] STO/DSOs may be conducted privately or on public, regulated stock exchange and are used to tokenize traditional assets such as company shares as well as more innovative ones like intellectual property, real estate,[104] art, or individual products. A number of companies are active in this space providing services for compliant tokenization, private STOs, and public STOs.

### Games

Main article: Finance:Blockchain game

Blockchain technology, such as cryptocurrencies and non-fungible tokens (NFTs), has been used in video games for monetization. Many live-service games offer in-game customization options, such as character skins or other in-game items, which the players can earn and trade with other players using in-game currency. Some games also allow for trading of virtual items using real-world currency, but this may be illegal in some countries where video games are seen as akin to gambling, and has led to gray market issues such as skin gambling, and thus publishers typically have shied away from allowing players to earn real-world funds from games.[105] Blockchain games typically allow players to trade these in-game items for cryptocurrency, which can then be exchanged for money.[106]

The first known game to use blockchain technologies was CryptoKitties, launched in November 2017, where the player would purchase NFTs with Ethereum cryptocurrency, each NFT consisting of a virtual pet that the player could breed with others to create offspring with combined traits as new NFTs.[107][106] The game made headlines in December 2017 when one virtual pet sold for more than US$100,000.[108] CryptoKitties also illustrated scalability problems for games on Ethereum when it created significant congestion on the Ethereum network in early 2018 with approximately 30% of all Ethereum transactions[clarification needed] being for the game.[109][110]

By the early 2020s, there had not been a breakout success in video games using blockchain, as these games tend to focus on using blockchain for speculation instead of more traditional forms of gameplay, which offers limited appeal to most players. Such games also represent a high risk to investors as their revenues can be difficult to predict.[106] However, limited successes of some games, such as Axie Infinity during the COVID-19 pandemic, and corporate plans towards metaverse content, refueled interest in the area of GameFi, a term describing the intersection of video games and financing typically backed by blockchain currency, in the second half of 2021.[111] Several major publishers, including Ubisoft, Electronic Arts, and Take Two Interactive, have stated that blockchain and NFT-based games are under serious consideration for their companies in the future.[112]

In October 2021, Valve Corporation banned blockchain games, including those using cryptocurrency and NFTs, from being hosted on its Steam digital storefront service, which is widely used for personal computer gaming, claiming that this was an extension of their policy banning games that offered in-game items with real-world value. Valve's prior history with gambling, specifically skin gambling, was speculated to be a factor in the decision to ban blockchain games.[113] Journalists and players responded positively to Valve's decision as blockchain and NFT games have a reputation for scams and fraud among most PC gamers,[105][113] and Epic Games, which runs the Epic Games Store in competition to Steam, said that they would be open to accepted blockchain games in the wake of Valve's refusal.[114]

### Supply chain

| Parts of this finance (those related to section) need to be updated. Please update this finance to reflect recent events or newly available information. (August 2023)

|

There have been several different efforts to employ blockchains in supply chain management.

* Precious commodities mining — Blockchain technology has been used for tracking the origins of gemstones and other precious commodities. In 2016, The Wall Street Journal reported that the blockchain technology company Everledger was partnering with IBM's blockchain-based tracking service to trace the origin of diamonds to ensure that they were ethically mined.[115] As of 2019, the Diamond Trading Company (DTC) has been involved in building a diamond trading supply chain product called Tracer.[116]
* Food supply — As of 2018, Walmart and IBM were running a trial to use a blockchain-backed system for supply chain monitoring for lettuce and spinach – all nodes of the blockchain were administered by Walmart and located on the IBM cloud.[117]
* Fashion industry — There is an opaque relationship between brands, distributors, and customers in the fashion industry, which prevents the sustainable and stable development of the fashion industry. Blockchain could make this information transparent, assisting sustainable development of the industry.[118]
* Motor vehicles — Mercedes-Benz and partner Icertis developed a blockchain prototype used to facilitate consistent documentation of contracts along the supply chain so that the ethical standards and contractual obligations required of its direct suppliers can be passed on to second tier suppliers and beyond.[119][120] In another project, the company uses blockchain technology to track the emissions of climate-relevant gases and the amount of secondary material along the supply chain for its battery cell manufacturers.[121]

### Domain names

There are several different efforts to offer domain name services via the blockchain. These domain names can be controlled by the use of a private key, which purports to allow for uncensorable websites. This would also bypass a registrar's ability to suppress domains used for fraud, abuse, or illegal content.[122]

Namecoin is a cryptocurrency that supports the ".bit" top-level domain (TLD). Namecoin was forked from bitcoin in 2011. The .bit TLD is not sanctioned by ICANN, instead requiring an alternative DNS root.[122] As of 2015, .bit was used by 28 websites, out of 120,000 registered names.[123] Namecoin was dropped by OpenNIC in 2019, due to malware and potential other legal issues.[124] Other blockchain alternatives to ICANN include The Handshake Network,[123] EmerDNS, and Unstoppable Domains.[122]

Specific TLDs include ".eth", ".luxe", and ".kred", which are associated with the Ethereum blockchain through the Ethereum Name Service (ENS). The .kred TLD also acts as an alternative to conventional cryptocurrency wallet addresses as a convenience for transferring cryptocurrency.[125]

### Other uses

Blockchain technology can be used to create a permanent, public, transparent ledger system for compiling data on sales, tracking digital use and payments to content creators, such as wireless users[126] or musicians.[127] The Gartner 2019 CIO Survey reported 2% of higher education respondents had launched blockchain projects and another 18% were planning academic projects in the next 24 months.[128] In 2017, IBM partnered with ASCAP and PRS for Music to adopt blockchain technology in music distribution.[129] Imogen Heap's Mycelia service has also been proposed as a blockchain-based alternative "that gives artists more control over how their songs and associated data circulate among fans and other musicians."[130][131]

New distribution methods are available for the insurance industry such as peer-to-peer insurance, parametric insurance and microinsurance following the adoption of blockchain.[132][133] The sharing economy and IoT are also set to benefit from blockchains because they involve many collaborating peers.[134] The use of blockchain in libraries is being studied with a grant from the U.S. Institute of Museum and Library Services.[135]

Other blockchain designs include Hyperledger, a collaborative effort from the Linux Foundation to support blockchain-based distributed ledgers, with projects under this initiative including Hyperledger Burrow (by Monax) and Hyperledger Fabric (spearheaded by IBM).[136][137][138] Another is Quorum, a permissioned private blockchain by JPMorgan Chase with private storage, used for contract applications.[139]

Oracle introduced a blockchain table feature in its Oracle 21c database.[69][70]

Blockchain is also being used in peer-to-peer energy trading.[140][141][142]

Lightweight blockchains, or simplified blockchains, are more suitable for internet of things (IoT) applications than conventional blockchains.[143] One experiment suggested that a lightweight blockchain-based network could accommodate up to 1.34 million authentication processes every second, which could be sufficient for resource-constrained IoT networks.[144]

Blockchain could be used in detecting counterfeits by associating unique identifiers to products, documents and shipments, and storing records associated with transactions that cannot be forged or altered.[145][146] It is however argued that blockchain technology needs to be supplemented with technologies that provide a strong binding between physical objects and blockchain systems,[147] as well as provisions for content creator verification ala KYC standards.[148] The EUIPO established an Anti-Counterfeiting Blockathon Forum, with the objective of "defining, piloting and implementing" an anti-counterfeiting infrastructure at the European level.[149][150] The Dutch Standardisation organisation NEN uses blockchain together with QR Codes to authenticate certificates.[151]

Beijing and Shanghai are among the cities designated by China to trial blockchain applications as January 30, 2022.[152] In Chinese legal proceedings, blockchain technology was first accepted as a method for authenticating internet evidence by the Hangzhou Internet Court in 2019 and has since been accepted by other Chinese courts.[153]: 123–125

## Blockchain interoperability

With the increasing number of blockchain systems appearing, even only those that support cryptocurrencies, blockchain interoperability is becoming a topic of major importance. The objective is to support transferring assets from one blockchain system to another blockchain system. Wegner[154] stated that "interoperability is the ability of two or more software components to cooperate despite differences in language, interface, and execution platform". The objective of blockchain interoperability is therefore to support such cooperation among blockchain systems, despite those kinds of differences.

There are already several blockchain interoperability solutions available.[155] They can be classified into three categories: cryptocurrency interoperability approaches, blockchain engines, and blockchain connectors.

Several individual IETF participants produced the draft of a blockchain interoperability architecture.[156]

## Energy consumption concerns

Some cryptocurrencies use blockchain mining, namely the peer-to-peer computer computations by which transactions are validated and verified. This requires a large amount of energy. In June 2018, the Bank for International Settlements criticized the use of public proof-of-work blockchains for their high energy consumption.[157][158][159]

Early concern over the high energy consumption was a factor in later blockchains such as Cardano (2017), Solana (2020) and Polkadot (2020) adopting the less energy-intensive proof-of-stake model. Researchers have estimated that bitcoin consumes 100,000 times as much energy as proof-of-stake networks.[160][161]

In 2021, a study by Cambridge University determined that bitcoin (at 121 terawatt-hours per year) used more electricity than Argentina (at 121TWh) and the Netherlands (109TWh).[162] According to Digiconomist, one bitcoin transaction required 708 kilowatt-hours of electrical energy, the amount an average U.S. household consumed in 24 days.[163]

In February 2021, U.S. Treasury secretary Janet Yellen called bitcoin "an extremely inefficient way to conduct transactions", saying "the amount of energy consumed in processing those transactions is staggering".[164] In March 2021, Bill Gates stated that "Bitcoin uses more electricity per transaction than any other method known to mankind", adding "It's not a great climate thing."[165]

Nicholas Weaver, of the International Computer Science Institute at the University of California, Berkeley, examined blockchain's online security, and the energy efficiency of proof-of-work public blockchains, and in both cases found it grossly inadequate.[166][167] The 31TWh-45TWh of electricity used for bitcoin in 2018 produced 17–23 million tonnes of CO
2.[168][169] By 2022, the University of Cambridge and Digiconomist estimated that the two largest proof-of-work blockchains, bitcoin and Ethereum, together used twice as much electricity in one year as the whole of Sweden, leading to the release of up to 120 million tonnes of CO
2 each year.[170]

Some cryptocurrency developers are considering moving from the proof-of-work model to the proof-of-stake model.[171] In Sept, 2022, Ethereum converted from proof-of-work to proof-of-stake.[172]

## Academic research

Blockchain panel discussion at the first IEEE Computer Society TechIgnite conference

In October 2014, the MIT Bitcoin Club, with funding from MIT alumni, provided undergraduate students at the Massachusetts Institute of Technology access to $100 of bitcoin. The adoption rates, as studied by Catalini and Tucker (2016), revealed that when people who typically adopt technologies early are given delayed access, they tend to reject the technology.[173] Many universities have founded departments focusing on crypto and blockchain, including MIT, in 2017. In the same year, Edinburgh became "one of the first big European universities to launch a blockchain course", according to the Financial Times.[174]

### Adoption decision

Motivations for adopting blockchain technology (an aspect of innovation adoption) have been investigated by researchers. For example, Janssen, et al. provided a framework for analysis,[175] and Koens & Poll pointed out that adoption could be heavily driven by non-technical factors.[176] Based on behavioral models, Li[177] has discussed the differences between adoption at the individual level and organizational levels.

### Collaboration

Scholars in business and management have started studying the role of blockchains to support collaboration.[178][179] It has been argued that blockchains can foster both cooperation (i.e., prevention of opportunistic behavior) and coordination (i.e., communication and information sharing). Thanks to reliability, transparency, traceability of records, and information immutability, blockchains facilitate collaboration in a way that differs both from the traditional use of contracts and from relational norms. Contrary to contracts, blockchains do not directly rely on the legal system to enforce agreements.[180] In addition, contrary to the use of relational norms, blockchains do not require a trust or direct connections between collaborators.

### Blockchain and internal audit

External video Blockchain Basics & Cryptography, Gary Gensler, Massachusetts Institute of Technology, 0:30[181]

The need for internal audits to provide effective oversight of organizational efficiency will require a change in the way that information is accessed in new formats.[182] Blockchain adoption requires a framework to identify the risk of exposure associated with transactions using blockchain. The Institute of Internal Auditors has identified the need for internal auditors to address this transformational technology. New methods are required to develop audit plans that identify threats and risks. The Internal Audit Foundation study, Blockchain and Internal Audit, assesses these factors.[183] The American Institute of Certified Public Accountants has outlined new roles for auditors as a result of blockchain.[184]

### Testnet

In blockchain technology, a testnet is an instance of a blockchain powered by the same or a newer version of the underlying software, to be used for testing and experimentation without risk to real funds or the main chain.[185] Testnet coins are separate and distinct from the official mainnet coins, don't have value, and can be obtained freely from faucets.[186]

Testnets allow for the development of blockchain applications without the risk of losing funds.[187]

Using testnets, a bug was discovered in the Bitcoin Core software that gave miners the ability to take down essential parts of the Bitcoin infrastructure (nodes) by sending a 'bad' block to the blockchain.[188]

### Mainnet

A mainnet (short for main network) is the fully operational version of a blockchain where real transactions occur, as opposed to a testnet. It is secured through consensus mechanisms like Proof of Work or Proof of Stake and supports smart contracts, token transfers, and decentralized applications.[189]

A mainnet launch marks the transition from a testnet to a live blockchain, involving security audits, network deployment, and token migration.[190]

### Journals

In September 2015, the first peer-reviewed academic journal dedicated to cryptocurrency and blockchain technology research, Ledger, was announced. The inaugural issue was published in December 2016.[191] The journal covers aspects of mathematics, computer science, engineering, law, economics and philosophy that relate to cryptocurrencies.[192][193] The journal encourages authors to digitally sign a file hash of submitted papers, which are then timestamped into the bitcoin blockchain. Authors are also asked to include a personal bitcoin address on the first page of their papers for non-repudiation purposes.[194]

## See also

* Changelog – a record of all notable changes made to a project
* Checklist – an informational aid used to reduce failure
* Economics of digitization
* Git – a version control system where the commit hash value depends on the previous commit hash value, also with Merkle tree inside[195]
* List of blockchains
* Privacy and blockchain
* Real-World Assets
* Version control – a record of all changes (mostly of software project) in a form of a graph

## References

1. ↑ Morris, David Z. (15 May 2016). "Leaderless, Blockchain-Based Venture Capital Fund Raises $100 Million, And Counting". Fortune. http://fortune.com/2016/05/15/leaderless-blockchain-vc-fund/.
2. ↑ 2.0 2.1 Popper, Nathan (21 May 2016). "A Venture Fund With Plenty of Virtual Capital, but No Capitalist". The New York Times. https://www.nytimes.com/2016/05/22/business/dealbook/crypto-ether-bitcoin-currency.html.
3. ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 "Blockchains: The great chain of being sure about things". The Economist. 31 October 2015. https://www.economist.com/news/briefing/21677228-technology-behind-bitcoin-lets-people-who-do-not-know-or-trust-each-other-build-dependable. "The technology behind bitcoin lets people who do not know or trust each other build a dependable ledger. This has implications far beyond the crypto currency."
4. ↑ 4.0 4.1 4.2 4.3 4.4 Narayanan, Arvind; Bonneau, Joseph; Felten, Edward; Miller, Andrew; Goldfeder, Steven (2016). Bitcoin and cryptocurrency technologies: a comprehensive introduction. Princeton, New Jersey: Princeton University Press. ISBN 978-0-691-17169-2.
5. ↑ Iansiti, Marco; Lakhani, Karim R. (January 2017). "The Truth About Blockchain". Harvard Business Review (Cambridge, Massachusetts: Harvard University). https://hbr.org/2017/01/the-truth-about-blockchain. "The technology at the heart of bitcoin and other virtual currencies, blockchain is an open, distributed ledger that can record transactions between two parties efficiently and in a verifiable and permanent way."
6. ↑ Oberhaus, Daniel (August 27, 2018). "The World's Oldest Blockchain Has Been Hiding in the New York Times Since 1995" (in en). https://www.vice.com/en/article/what-was-the-first-blockchain/.
7. ↑ Lunn, Bernard (10 February 2018). "Blockchain may finally disrupt payments from Micropayments to credit cards to SWIFT". https://dailyfintech.com/2018/02/10/bitcoin-will-finally-disrupt-the-credit-card-rails/.
8. ↑ 8.0 8.1 8.2 8.3 8.4 Hampton, Nikolai (5 September 2016). "Understanding the blockchain hype: Why much of it is nothing more than snake oil and spin". Computerworld. https://www2.computerworld.com.au/article/606253/understanding-blockchain-hype-why-much-it-nothing-more-than-snake-oil-spin/. Retrieved 2016-09-05.
9. ↑ 9.0 9.1 Bakos, Yannis; Halaburda, Hanna; Mueller-Bloch, Christoph (February 2021). "When Permissioned Blockchains Deliver More Decentralization Than Permissionless". Communications of the ACM 64 (2): 20–22. doi:10.1145/3442371. https://pure.itu.dk/portal/da/publications/e29df7d1-e939-43d3-9f38-b97d983e730d.
10. ↑ Sherman, Alan T.; Javani, Farid; Zhang, Haibin; Golaszewski, Enis (January 2019). "On the Origins and Variations of Blockchain Technologies". IEEE Security & Privacy 17 (1): 72–77. doi:10.1109/MSEC.2019.2893730. ISSN 1558-4046. Bibcode: 2019ISPri..17a..72S.
11. ↑ Download PDF of dissertation from Dr. Chaum's website
12. ↑ Haber, Stuart; Stornetta, W. Scott (January 1991). "How to time-stamp a digital document". Journal of Cryptology 3 (2): 99–111. doi:10.1007/bf00196791.
13. ↑ Bayer, Dave; Haber, Stuart; Stornetta, W. Scott (March 1992). "Improving the Efficiency and Reliability of Digital Time-Stamping". Sequences. 2. pp. 329–334. doi:10.1007/978-1-4613-9323-8_24. ISBN 978-1-4613-9325-2.
14. ↑ Oberhaus, Daniel (2018-08-27). "The World's Oldest Blockchain Has Been Hiding in the New York Times Since 1995" (in en). https://www.vice.com/en/article/what-was-the-first-blockchain/.
15. ↑ Nian, Lam Pak; Chuen, David LEE Kuo (2015). "A Light Touch of Regulation for Virtual Currencies". in Chuen, David LEE Kuo. Handbook of Digital Currency: Bitcoin, Innovation, Financial Instruments, and Big Data. Academic Press. p. 319. ISBN 978-0-12-802351-8.
16. ↑ "Blockchain Size". https://www.blockchain.com/en/charts/blocks-size?scale=1×pan=all&showDataPoints=true.
17. ↑ Johnsen, Maria (12 May 2020) (in en). Blockchain in Digital Marketing: A New Paradigm of Trust. Maria Johnsen. p. 6. ISBN 979-8-6448-7308-1. https://books.google.com/books?id=uVbjDwAAQBAJ&pg=PA6.
18. ↑ "The future of blockchain in 8 charts". Raconteur. 27 June 2016. http://raconteur.net/business/the-future-of-blockchain-in-8-charts.
19. ↑ "Hype Killer - Only 1% of Companies Are Using Blockchain, Gartner Reports | Artificial Lawyer" (in en-GB). Artificial Lawyer. 4 May 2018. https://www.artificiallawyer.com/2018/05/04/hype-killer-only-1-of-companies-are-using-blockchain-gartner-reports/.
20. ↑ Kasey Panetta. (31 October 2018). "Digital Business: CIO Agenda 2019: Exploit Transformational Technologies." Gartner website Retrieved 27 March 2021.
21. ↑ Armstrong, Stephen (7 November 2016). "Move over Bitcoin, the blockchain is only just getting started". Wired. https://www.wired.co.uk/article/unlock-the-blockchain.
22. ↑ Catalini, Christian; Gans, Joshua S. (23 November 2016). "Some Simple Economics of the Blockchain". SSRN. doi:10.2139/ssrn.2874598. http://www.nber.org/papers/w22952.pdf. Retrieved 16 September 2019.
23. ↑ Tapscott, Don; Tapscott, Alex (8 May 2016). "Here's Why Blockchains Will Change the World". Fortune. http://fortune.com/2016/05/08/why-blockchains-will-change-the-world/. Retrieved 16 November 2016.
24. ↑ Bheemaiah, Kariappa (January 2015). "Block Chain 2.0: The Renaissance of Money". Wired. https://www.wired.com/insights/2015/01/block-chain-2-0/. Retrieved 13 November 2016.
25. ↑ Chen, Huashan; Pendleton, Marcus; Njilla, Laurent; Xu, Shouhuai (12 June 2020). "A Survey on Ethereum Systems Security: Vulnerabilities, Attacks, and Defenses". ACM Computing Surveys 53 (3): 3–4. doi:10.1145/3391195. ISSN 0360-0300.
26. ↑ Shishir, Bhatia (2006-02-02). Structured Information Flow (SIF) Framework for Automating End-to-End Information Flow for Large Organizations (Thesis). Virginia Tech. Archived from the original on 4 April 2022. Retrieved 28 March 2022.
27. ↑ 27.0 27.1 27.2 27.3 Bhaskar, Nirupama Devi; Chuen, David LEE Kuo (2015). "Bitcoin Mining Technology". Handbook of Digital Currency. pp. 45–65. doi:10.1016/B978-0-12-802117-0.00003-5. ISBN 978-0-12-802117-0. https://ink.library.smu.edu.sg/lkcsb_research/4216.
28. ↑ Knirsch, Unterweger & Engel 2019, p. 2.
29. ↑ 29.0 29.1 29.2 Antonopoulos, Andreas (20 February 2014). "Bitcoin security model: trust by computation". O'Reilly. http://radar.oreilly.com/2014/02/bitcoin-security-model-trust-by-computation.html.
30. ↑ 30.0 30.1 Antonopoulos, Andreas M. (2014). Mastering Bitcoin. Unlocking Digital Cryptocurrencies. Sebastopol, CA: O'Reilly Media. ISBN 978-1449374037. http://chimera.labs.oreilly.com/books/1234000001802/ch01.html. Retrieved 3 November 2015.
31. ↑ Nakamoto, Satoshi (October 2008). "Bitcoin: A Peer-to-Peer Electronic Cash System". bitcoin.org. https://bitcoin.org/bitcoin.pdf.
32. ↑ "Permissioned Blockchains". Monax. https://monax.io/explainers/permissioned_blockchains/.
33. ↑ Kumar, Randhir; Tripathi, Rakesh (November 2019). "Implementation of Distributed File Storage and Access Framework using IPFS and Blockchain". 2019 Fifth International Conference on Image Information Processing (ICIIP). IEEE. pp. 246–251. doi:10.1109/iciip47207.2019.8985677. ISBN 978-1-7281-0899-5.
34. ↑ Lee, Timothy (12 March 2013). "Major glitch in Bitcoin network sparks sell-off; price temporarily falls 23%". Arstechnica. https://arstechnica.com/business/2013/03/major-glitch-in-bitcoin-network-sparks-sell-off-price-temporarily-falls-23/.
35. ↑ Smith, Oli (21 January 2018). "Bitcoin price RIVAL: Cryptocurrency 'faster than bitcoin' will CHALLENGE market leaders". Express. https://www.express.co.uk/finance/city/907536/cryptocurrency-bitcoin-market-leader-cash-ripple-ethereum.
36. ↑ "Bitcoin split in two, here's what that means". CNN. 2017-08-01. https://money.cnn.com/2017/08/01/technology/business/bitcoin-cash-new-currency/index.html.
37. ↑ Hughes, Laurie; Dwivedi, Yogesh K.; Misra, Santosh K.; Rana, Nripendra P.; Raghavan, Vishnupriya; Akella, Viswanadh (December 2019). "Blockchain research, practice and policy: Applications, benefits, limitations, emerging research themes and research agenda" (in en). International Journal of Information Management 49: 114–129. doi:10.1016/j.ijinfomgt.2019.02.005. https://linkinghub.elsevier.com/retrieve/pii/S0268401219302014. Retrieved 20 November 2022.
38. ↑ Roberts, Jeff John (29 May 2018). "Bitcoin Spinoff Hacked in Rare '51% Attack'" (in en). Fortune. https://fortune.com/2018/05/29/bitcoin-gold-hack/.
39. ↑ 39.0 39.1 Brito, Jerry; Castillo, Andrea (2013). ﻿Bitcoin: A Primer for Policymakers﻿ (Report). Fairfax, VA: Mercatus Center, George Mason University. http://mercatus.org/sites/default/files/Brito_BitcoinPrimer.pdf. Retrieved 22 October 2013.
40. ↑ Raval, Siraj (2016). Decentralized Applications: Harnessing Bitcoin's Blockchain Technology. O'Reilly Media, Inc.. pp. 1–2. ISBN 978-1-4919-2452-5. https://books.google.com/books?id=fvywDAAAQBAJ.
41. ↑ Kopfstein, Janus (12 December 2013). "The Mission to Decentralize the Internet". The New Yorker. https://www.newyorker.com/tech/elements/the-mission-to-decentralize-the-internet. Retrieved 30 December 2014. "The network's 'nodes' — users running the bitcoin software on their computers — collectively check the integrity of other nodes to ensure that no one spends the same coins twice. All transactions are published on a shared public ledger, called the 'block chain.'".
42. ↑ Gervais, Arthur; Karame, Ghassan O.; Capkun, Vedran; Capkun, Srdjan. "Is Bitcoin a Decentralized Currency?". InfoQ & IEEE computer society. https://www.infoq.com/articles/is-bitcoin-a-decentralized-currency/.
43. ↑ 43.0 43.1 43.2 Deirmentzoglou, Evangelos; Papakyriakopoulos, Georgios; Patsakis, Constantinos (2019). "A Survey on Long-Range Attacks for Proof of Stake Protocols". IEEE Access 7: 28712–28725. doi:10.1109/ACCESS.2019.2901858. Bibcode: 2019IEEEA...728712D.
44. ↑ 44.0 44.1 Voorhees, Erik (30 October 2015). "It's All About the Blockchain". http://moneyandstate.com/its-all-about-the-blockchain/.
45. ↑ Reutzel, Bailey (13 July 2015). "A Very Public Conflict Over Private Blockchains". New York, NY: SourceMedia, Inc.. http://www.paymentssource.com/news/technology/a-very-public-confluct-over-private-blockchains-3021831-1.html.
46. ↑ 46.0 46.1 "Moneybeat/BitBeat: Blockchains Without Coins Stir Tensions in Bitcoin Community". The Wall Street Journal. 15 April 2015. https://blogs.wsj.com/moneybeat/2015/04/14/bitbeat-blockchains-without-coins-stir-tensions-in-bitcoin-community/. Retrieved 18 June 2016.
47. ↑ "The 'Blockchain Technology' Bandwagon Has A Lesson Left To Learn". 3 November 2015. http://news.dinbits.com/2015/11/the-blockchain-technology-bandwagon-has.html.
48. ↑ DeRose, Chris (26 June 2015). "Why the Bitcoin Blockchain Beats Out Competitors". http://www.americanbanker.com/bankthink/why-the-bitcoin-blockchain-beats-out-competitors-1075100-1.html.
49. ↑ Greenspan, Gideon (19 July 2015). "Ending the bitcoin vs blockchain debate". http://www.multichain.com/blog/2015/07/bitcoin-vs-blockchain-debate/.
50. ↑ Tapscott, Don; Tapscott, Alex (May 2016). The Blockchain Revolution: How the Technology Behind Bitcoin is Changing Money, Business, and the World. Portfolio/Penguin. ISBN 978-0-670-06997-2.
51. ↑ Barry, Levine (11 June 2018). "A new report bursts the blockchain bubble". MarTech. https://martechtoday.com/a-new-report-bursts-the-blockchain-bubble-216959.
52. ↑ 52.0 52.1 Ovenden, James. "Blockchain Top Trends In 2017". The Innovation Enterprise. https://channels.theinnovationenterprise.com/articles/blockchain-top-trends-in-2017.
53. ↑ 53.0 53.1 Bob Marvin (30 August 2017). "Blockchain: The Invisible Technology That's Changing the World". PC MAG Australia (ZiffDavis, LLC). http://au.pcmag.com/amazon-web-services/46389/feature/blockchain-the-invisible-technology-thats-changing-the-world.
54. ↑ O'Keeffe, M.; Terzi, A. (7 July 2015). "The political economy of financial crisis policy". http://bruegel.org/2015/07/the-political-economy-of-financial-crisis-policy/.
55. ↑ Dr Garrick Hileman & Michel Rauchs (2017). "GLOBAL CRYPTOCURRENCY BENCHMARKING STUDY". Cambridge Centre for Alternative Finance (University of Cambridge Judge Business School). https://cdn.crowdfundinsider.com/wp-content/uploads/2017/04/Global-Cryptocurrency-Benchmarking-Study.pdf. Retrieved 15 May 2019.
56. ↑ Raymaekers, Wim (March 2015). "Cryptocurrency Bitcoin: Disruption, challenges and opportunities" (in en). Journal of Payments Strategy & Systems 9 (1): 30–46. doi:10.69554/FBUJ3107. https://www.ingentaconnect.com/content/hsp/jpss/2015/00000009/00000001/art00005. Retrieved 2019-05-15.
57. ↑ "Why Crypto Companies Still Can't Open Checking Accounts" (in en). 2019-03-03. https://www.bloomberg.com/news/articles/2019-03-03/why-crypto-companies-still-can-t-open-checking-accounts.
58. ↑ Christian Brenig, Rafael Accorsi & Günter Müller (Spring 2015). "Economic Analysis of Cryptocurrency Backed Money Laundering". Association for Information Systems AIS Electronic Library (AISeL). https://aisel.aisnet.org/cgi/viewcontent.cgi?article=1019&context=ecis2015_cr. Retrieved 15 May 2019.
59. ↑ Greenberg, Andy (25 January 2017). "Monero, the Drug Dealer's Cryptocurrency of Choice, Is on Fire". Wired. ISSN 1059-1028. https://www.wired.com/2017/01/monero-drug-dealers-cryptocurrency-choice-fire/.
60. ↑ Orcutt, Mike. "It's getting harder to hide money in Bitcoin" (in en-US). https://www.technologyreview.com/s/608763/criminals-thought-bitcoin-was-the-perfect-hiding-place-they-thought-wrong/.
61. ↑ "Explainer: 'Privacy coin' Monero offers near total anonymity" (in en). Reuters. 15 May 2019. https://uk.reuters.com/article/us-crypto-currencies-altcoins-explainer-idUKKCN1SL0F0.
62. ↑ "Blockchain". Standards Australia. https://www.standards.org.au/engagement-events/flagship-projects/blockchain.
63. ↑ 63.0 63.1 "ISO/TC 307 Blockchain and distributed ledger technologies". ISO. 15 September 2020. https://www.iso.org/committee/6266604.html.
64. ↑ Deshmukh, Sumedha; Boulais, Océane; Koens, Tommy. "Global Standards Mapping Initiative: An overview of blockchain technical standards". World Economic Forum. http://www3.weforum.org/docs/WEF_GSMI_Technical_Standards_2020.pdf.
65. ↑ "Blockchain Overview". NIST. 25 September 2019. https://www.nist.gov/blockchain. Retrieved 21 June 2021.
66. ↑ "CEN and CENELEC publish a White Paper on standards in Blockchain & Distributed Ledger Technologies". CENELEC. https://www.cencenelec.eu/news/brief_news/Pages/TN-2018-085.aspx.
67. ↑ "Standards". IEEE Blockchain. https://blockchain.ieee.org/standards.
68. ↑ Hardjono, Thomas. "An Interoperability Architecture for Blockchain/DLT Gateways". IETF. https://www.ietf.org/id/draft-hardjono-blockchain-interop-arch-02.txt.
69. ↑ 69.0 69.1 "Details: Oracle Blockchain Table". https://docs.oracle.com/en/database/oracle/oracle-database/21/nfcon/details-oracle-blockchain-table-282449857.html.
70. ↑ 70.0 70.1 "Oracle Blockchain Table". https://docs.oracle.com/en/database/oracle/oracle-database/21/nfcon/oracle-blockchain-table-268779556.html.
71. ↑ "How Companies Can Leverage Private Blockchains to Improve Efficiency and Streamline Business Processes". https://perfectial.com/blog/leveraging-private-blockchains-improve-efficiency-streamline-business-processes/.
72. ↑ [Distributed Ledger Technology: Hybrid Approach, Front-to-Back Designing and Changing Trade Processing Infrastructure, By Martin Walker, First published:, 24 OCT 2018 ISBN 978-1-78272-389-9]
73. ↑ Siraj Raval (18 July 2016). Decentralized Applications: Harnessing Bitcoin's Blockchain Technology. "O'Reilly Media, Inc.". pp. 22–. ISBN 978-1-4919-2452-5. https://books.google.com/books?id=fvywDAAAQBAJ&pg=PA22.
74. ↑ Niaz Chowdhury (16 August 2019). Inside Blockchain, Bitcoin, and Cryptocurrencies. CRC Press. pp. 22–. ISBN 978-1-00-050770-6. https://books.google.com/books?id=_HatDwAAQBAJ&pg=PA22.
75. ↑ U.S. Patent 10,438,290
76. ↑ Dib, Omar; Brousmiche, Kei-Leo; Durand, Antoine; Thea, Eric; Hamida, Elyes Ben. "Consortium Blockchains: Overview, Applications and Challenges". International Journal on Advances in Telecommunications 11 (1/2): 51–64.
77. ↑ Bhattacharyya, Anchita. "Top 10 Blockchain Technology Trends for 2025". https://www.intelligenceinsights.net/blockchain/blockchain-technology-trends/.
78. ↑ Katie Martin (27 September 2016). "CLS dips into blockchain to net new currencies". Financial Times. https://www.ft.com/content/c905b6fc-4dd2-3170-9d2a-c79cdbb24f16.
79. ↑ 79.0 79.1 79.2 Kimani, Danson; Adams, Kweku; Attah-Boakye, Rexford; Ullah, Subhan; Frecknall-Hughes, Jane; Kim, Ja (2020-12-01). "Blockchain, business and the fourth industrial revolution: Whence, whither, wherefore and how?". Technological Forecasting and Social Change 161. doi:10.1016/j.techfore.2020.120254. ISSN 0040-1625. https://linkinghub.elsevier.com/retrieve/pii/S0040162520310805.
80. ↑ Castillo, Michael (16 April 2019). "blockchain 50: Billion Dollar Babies". Financial Website (SourceMedia). https://www.forbes.com/sites/michaeldelcastillo/2019/04/16/blockchain-50-billion-dollar-babies/.
81. ↑ Davies, Steve (2018). "PwC's Global Blockchain Survey". Financial Website (SourceMedia). https://www.pwc.com/gx/en/industries/technology/blockchain/blockchain-in-business.html.
82. ↑ "BBC Radio 4 - Things That Made the Modern Economy, Series 2, Blockchain" (in en-GB). https://www.bbc.co.uk/programmes/m0008b9v.
83. ↑ Liu, Shanhong (13 March 2020). "Blockchain - Statistics & Facts". Statistics Website (SourceMedia). https://www.statista.com/topics/5122/blockchain/#dossierSummary__chapter6.
84. ↑ Du, Wenbo; Ma, Xiaozhi; Yuan, Hongping; Zhu, Yue (2022-08-01). "Blockchain technology-based sustainable management research: the status quo and a general framework for future application" (in en). Environmental Science and Pollution Research 29 (39): 58648–58663. doi:10.1007/s11356-022-21761-2. ISSN 1614-7499. PMID 35794327. PMC 9261142. Bibcode: 2022ESPR...2958648D. https://doi.org/10.1007/s11356-022-21761-2.
85. ↑ 85.0 85.1 85.2 85.3 Narayanan, Arvind; Bonner, Joseph; Clark, Andrew; Felten, Edward W.; Kroll, Joshua A.; Wallach, Daniel S. (2016). Bitcoin and Cryptocurrency Technologies: A Comprehensive Introduction. Princeton University Press. ISBN 978-0-691-17169-2.
86. ↑ 86.0 86.1 86.2 Iansiti, Marco; Lakhani, Karim R. (January 2017). "The Truth About Blockchain". Harvard Business Review. https://hbr.org/2017/01/the-truth-about-blockchain. Retrieved 17 January 2017. "The technology at the heart of bitcoin and other virtual currencies, blockchain is an open, distributed ledger that can record transactions between two parties efficiently and in a verifiable and permanent way.".
87. ↑ Raval, Siraj (2016). Decentralized Applications: Harnessing Bitcoin's Blockchain Technology. O'Reilly Media, Inc.. ISBN 978-1-4919-2452-5. OCLC 968277125.
88. ↑ Catalini, Christian. "How Blockchain Technology Will Impact the Digital Economy". https://www.forbes.com/sites/forbestechcouncil/2017/05/08/how-blockchain-technology-will-impact-the-digital-economy/.
89. ↑ Tosato, Andrea; Odinet, Christopher K. (2025). "Digital Assets and the Property Question". Florida Law Review forthcoming. https://papers.ssrn.com/sol3/papers.cfm?abstract_id=5151907.
90. ↑ Franco, Pedro (2014). Understanding Bitcoin: Cryptography, Engineering and Economics. John Wiley & Sons. p. 9. ISBN 978-1-119-01916-9. https://books.google.com/books?id=YHfCBwAAQBAJ. Retrieved 4 January 2017.
91. ↑ The impact of blockchain technology on finance : a catalyst for change. London, UK. 16 July 2018. ISBN 978-1-912179-15-2. OCLC 1059331326.
92. ↑ Governatori, Guido; Idelberger, Florian; Milosevic, Zoran; Riveret, Regis; Sartor, Giovanni; Xu, Xiwei (2018). "On legal contracts, imperative and declarative smart contracts, and blockchain systems" (in en). Artificial Intelligence and Law 26 (4): 33. doi:10.1007/s10506-018-9223-3.
93. ↑ Virtual Currencies and Beyond: Initial Considerations. IMF Discussion Note. International Monetary Fund. 2016. p. 23. ISBN 978-1-5135-5297-2. https://www.imf.org/external/pubs/ft/sdn/2016/sdn1603.pdf. Retrieved 2018-04-19.
94. ↑ Epstein, Jim (6 May 2016). "Is Blockchain Technology a Trojan Horse Behind Wall Street's Walled Garden?". Reason. http://reason.com/reasontv/2016/05/06/bitcoin-consensus-blockchain-wall-street. "mainstream misgivings about working with a system that's open for anyone to use. Many banks are partnering with companies building so-called private blockchains that mimic some aspects of Bitcoin's architecture except they're designed to be closed off and accessible only to chosen parties. ... [but some believe] that open and permission-less blockchains will ultimately prevail even in the banking sector simply because they're more efficient."
95. ↑ Redrup, Yolanda (29 June 2016). "ANZ backs private blockchain, but won't go public". Australia Financial Review. http://www.afr.com/technology/anz-backs-private-blockchain-but-wont-go-public-20160629-gpuf9z. "Blockchain networks can be either public or private. Public blockchains have many users and there are no controls over who can read, upload or delete the data and there are an unknown number of pseudonymous participants. In comparison, private blockchains also have multiple data sets, but there are controls in place over who can edit data and there are a known number of participants."
96. ↑ Shah, Rakesh (1 March 2018). "How Can The Banking Sector Leverage Blockchain Technology?". PostBox Communications Blog. http://www.postboxcommunications.com/blog/can-banking-sector-leverage-blockchain-technology/. "Banks preferably have a notable interest in utilizing Blockchain Technology because it is a great source to avoid fraudulent transactions. Blockchain is considered hassle free, because of the extra level of security it offers."
97. ↑ Kelly, Jemima (28 September 2016). "Banks adopting blockchain 'dramatically faster' than expected: IBM". Reuters. https://www.reuters.com/article/us-tech-blockchain-ibm-idUSKCN11Y28D.
98. ↑ Arnold, Martin (23 September 2013). "IBM in blockchain project with China UnionPay". Financial Times. https://www.ft.com/content/719f4e7e-80e1-11e6-bc52-0c7211ef3198.
99. ↑ Ravichandran, Arvind; Fargo, Christopher; Kappos, David; Portilla, David; Buretta, John; Ngo, Minh Van; Rosenthal-Larrea, Sasha (28 January 2022). "Blockchain in the Banking Sector: A Review of the Landscape and Opportunities". https://corpgov.law.harvard.edu/2022/01/28/blockchain-in-the-banking-sector-a-review-of-the-landscape-and-opportunities/.
100. ↑ "UBS leads team of banks working on blockchain settlement system". Reuters. 24 August 2016. https://www.reuters.com/article/us-banks-blockchain-ubs-idUSKCN10Z147.
101. ↑ "Cryptocurrency Blockchain". https://www.capgemini.com/beyond-the-buzz/cryptocurrency-blockchain.
102. ↑ Kelly, Jemima (31 October 2017). "Top banks and R3 build blockchain-based payments system". Reuters. https://www.reuters.com/article/us-banks-blockchain-r3/top-banks-and-r3-build-blockchain-based-payments-system-idUSKBN1D00ZB.
103. ↑ "Are Token Assets the Securities of Tomorrow?". Deloitte. February 2019. https://www2.deloitte.com/content/dam/Deloitte/lu/Documents/technology/lu-token-assets-securities-tomorrow.pdf.
104. ↑ Hammerberg, Jeff (November 7, 2021). "Potential impact of blockchain on real estate". Washington Blade. https://www.washingtonblade.com/2021/11/07/potential-impact-of-blockchain-on-real-estate/.
105. ↑ 105.0 105.1 Clark, Mitchell (15 October 2021). "Valve bans blockchain games and NFTs on Steam, Epic will try to make it work" (in en). The Verge. https://www.theverge.com/2021/10/15/22728425/valve-steam-blockchain-nft-crypto-ban-games-age-of-rust.
106. ↑ 106.0 106.1 106.2 Mozuch, Mo (April 29, 2021). "Blockchain Games Twist The Fundamentals Of Online Gaming". Inverse. https://www.inverse.com/gaming/blockchain-games-online-gaming.
107. ↑ "Internet firms try their luck at blockchain games". Asia Times. 22 February 2018. https://asiatimes.com/article/internet-firms-try-luck-blockchain-games/.
108. ↑ Evelyn Cheng (6 December 2017). "Meet CryptoKitties, the $100,000 digital beanie babies epitomizing the cryptocurrency mania". CNBC. https://www.cnbc.com/2017/12/06/meet-cryptokitties-the-new-digital-beanie-babies-selling-for-100k.html.
109. ↑ Laignee Barron (13 February 2018). "CryptoKitties is Going Mobile. Can Ethereum Handle the Traffic?". Fortune. http://fortune.com/2018/02/13/cryptokitties-ethereum-ios-launch-china-ether/.
110. ↑ "CryptoKitties craze slows down transactions on Ethereum". 12 May 2017. https://www.bbc.com/news/technology-42237162.
111. ↑ Wells, Charlie; Egkolfopoulou, Misrylena (October 30, 2021). "Into the Metaverse: Where Crypto, Gaming and Capitalism Collide". Bloomberg News. https://www.bloomberg.com/news/features/2021-10-30/what-is-the-metaverse-where-crypto-nft-capitalism-collide-in-games-like-axie.
112. ↑ Orland, Kyle (November 4, 2021). "Big-name publishers see NFTs as a big part of gaming's future". Ars Technica. https://arstechnica.com/gaming/2021/11/big-name-publishers-see-nfts-as-a-big-part-of-gamings-future/.
113. ↑ 113.0 113.1 Knoop, Joseph (15 October 2021). "Steam bans all games with NFTs or cryptocurrency" (in en). PC Gamer. https://www.pcgamer.com/steam-bans-nfts-cryptocurrencies-blockchain/.
114. ↑ Clark, Mitchell (October 15, 2021). "Epic says it's 'open' to blockchain games after Steam bans them". The Verge. https://www.theverge.com/2021/10/15/22729050/epic-game-store-open-to-blockchain-cryptocurrency-nft-games.
115. ↑ Nash, Kim S. (14 July 2016). "IBM Pushes Blockchain into the Supply Chain". The Wall Street Journal. https://www.wsj.com/articles/ibm-pushes-blockchain-into-the-supply-chain-1468528824.
116. ↑ Gstettner, Stefan (July 30, 2019). "How Blockchain Will Redefine Supply Chain Management". The Wharton School of the University of Pennsylvania. https://knowledge.wharton.upenn.edu/article/blockchain-supply-chain-management.
117. ↑ Corkery, Michael; Popper, Nathaniel (24 September 2018). "From Farm to Blockchain: Walmart Tracks Its Lettuce". The New York Times. https://www.nytimes.com/2018/09/24/business/walmart-blockchain-lettuce.html.
118. ↑ "Blockchain basics: Utilizing blockchain to improve sustainable supply chains in fashion" (in en). Strategic Direction 37 (5): 25–27. 2021-06-08. doi:10.1108/SD-03-2021-0028. ISSN 0258-0543. https://www.emerald.com/insight/content/doi/10.1108/SD-03-2021-0028/full/html. Retrieved 30 April 2022.
119. ↑ Mercedes-Benz Group AG, Once round the block, please! , accessed 24 August 2023
120. ↑ Green, W., Mercedes tests blockchain to improve supply chain transparency , Supply Management, published 25 February 2019, accessed 24 August 2023
121. ↑ Mercedes-Benz AG, Mercedes-Benz Cars drives "Ambition2039" in the supply chain: blockchain pilot project provides transparency on CO₂ emissions , published 30 January 2020, accessed 24 August 2023
122. ↑ 122.0 122.1 122.2 Sanders, James (August 28, 2019). "Blockchain-based Unstoppable Domains is a rehash of a failed idea" (in en). https://www.techrepublic.com/article/blockchain-based-unstoppable-domains-is-a-rehash-of-a-failed-idea/.
123. ↑ 123.0 123.1 Orcutt, Mike (June 4, 2019). "The ambitious plan to reinvent how websites get their names" (in en). MIT Technology Review. https://www.technologyreview.com/2019/06/04/239039/the-ambitious-plan-to-make-the-internets-phone-book-more-trustworthy/.
124. ↑ Cimpanu, Catalin (July 17, 2019). "OpenNIC drops support for .bit domain names after rampant malware abuse" (in en). ZDNet. https://www.zdnet.com/article/opennic-drops-support-for-bit-domain-names-after-rampant-malware-abuse/.
125. ↑ ".Kred launches as dual DNS and ENS domain" (in en-US). 2020-03-06. https://domainnamewire.com/2020/03/06/kred-blockchain-domain/.
126. ↑ K. Kotobi, and S. G. Bilen, "Secure Blockchains for Dynamic Spectrum Access : A Decentralized Database in Moving Cognitive Radio Networks Enhances Security and User Access", IEEE Vehicular Technology Magazine, 2018.
127. ↑ "Blockchain Could Be Music's Next Disruptor". 22 September 2016. http://fortune.com/2016/09/22/blockchain-music-disruption/.
128. ↑ Susan Moore. (16 October 2019). "Digital Business: 4 Ways Blockchain Will Transform Higher Education". Gartner website Retrieved 27 March 2021.
129. ↑ "ASCAP, PRS and SACEM Join Forces for Blockchain Copyright System". Music Business Worldwide. 9 April 2017. http://www.musicbusinessworldwide.com/ascap-prs-sacem-join-forces-blockchain-copyright-system/.
130. ↑ Burchardi, K.; Harle, N. (20 January 2018). "The blockchain will disrupt the music business and beyond". Wired UK. https://www.wired.co.uk/article/blockchain-disrupting-music-mycelia. Retrieved 8 May 2018.
131. ↑ Bartlett, Jamie (6 September 2015). "Imogen Heap: saviour of the music industry?". https://www.theguardian.com/music/2015/sep/06/imogen-heap-saviour-of-music-industry.
132. ↑ Wang, Kevin; Safavi, Ali (29 October 2016). "Blockchain is empowering the future of insurance". AOL Inc. https://techcrunch.com/2016/10/29/blockchain-is-empowering-the-future-of-insurance/.
133. ↑ Gatteschi, Valentina; Lamberti, Fabrizio; Demartini, Claudio; Pranteda, Chiara; Santamaría, Víctor (20 February 2018). "Blockchain and Smart Contracts for Insurance: Is the Technology Mature Enough?" (in en). Future Internet 10 (2): 20. doi:10.3390/fi10020020.
134. ↑ "Blockchain reaction: Tech companies plan for critical mass". Ernst & Young. p. 5. http://www.ey.com/Publication/vwLUAssets/ey-blockchain-reaction-tech-companies-plan-for-critical-mass/$FILE/ey-blockchain-reaction.pdf.
135. ↑ Carrie Smith. Blockchain Reaction: How library professionals are approaching blockchain technology and its potential impact. American Libraries March 2019.
136. ↑ "IBM Blockchain based on Hyperledger Fabric from the Linux Foundation" (in en-US). 9 January 2018. https://www.ibm.com/blockchain/hyperledger.html.
137. ↑ Hyperledger (22 January 2019). "Announcing Hyperledger Grid, a new project to help build and deliver supply chain solutions!". https://www.hyperledger.org/blog/2019/01/22/announcing-hyperledger-grid-a-new-project-to-help-build-and-deliver-supply-chain-solutions.
138. ↑ Mearian, Lucas (23 January 2019). "Grid, a new project from the Linux Foundation, will offer developers tools to create supply chain-specific applications running atop distributed ledger technology". Computerworld. https://www.computerworld.com/article/3336036/blockchain/linuxs-hyperledger-to-give-developers-supply-chain-building-blocks.html.
139. ↑ "Why J.P. Morgan Chase Is Building a Blockchain on Ethereum". http://fortune.com/2016/10/04/jp-morgan-chase-blockchain-ethereum-quorum/.
140. ↑ Andoni, Merlinda; Robu, Valentin; Flynn, David; Abram, Simone; Geach, Dale; Jenkins, David; McCallum, Peter; Peacock, Andrew (2019). "Blockchain technology in the energy sector: A systematic review of challenges and opportunities". Renewable and Sustainable Energy Reviews 100: 143–174. doi:10.1016/j.rser.2018.10.014. Bibcode: 2019RSERv.100..143A.
141. ↑ "This Blockchain-Based Energy Platform Is Building A Peer-To-Peer Grid". Fast Company. 16 October 2017. https://www.fastcompany.com/40479952/this-blockchain-based-energy-platform-is-building-a-peer-to-peer-grid.
142. ↑ "Blockchain-based microgrid gives power to consumers in New York". https://www.newscientist.com/article/2079334-blockchain-based-microgrid-gives-power-to-consumers-in-new-york/.
143. ↑ Alassaf, Norah; Gutub, Adnan; Parah, Shabir A.; Al Ghamdi, Manal (December 2019). "Enhancing speed of SIMON: A light-weight-cryptographic algorithm for IoT applications" (in en). Multimedia Tools and Applications 78 (23): 32633–32657. doi:10.1007/s11042-018-6801-z. ISSN 1380-7501. http://link.springer.com/10.1007/s11042-018-6801-z.
144. ↑ Khan, Safiullah; Lee, Wai-Kong; Hwang, Seong Oun (2021). "AEchain: A lightweight blockchain for IoT applications". IEEE Consumer Electronics Magazine 11 (2): 64–76. doi:10.1109/MCE.2021.3060373. ISSN 2162-2256.
145. ↑ Ma, Jinhua; Lin, Shih-Ya; Chen, Xin; Sun, Hung-Min; Chen, Yeh-Cheng; Wang, Huaxiong (2020). "A Blockchain-Based Application System for Product Anti-Counterfeiting". IEEE Access 8: 77642–77652. doi:10.1109/ACCESS.2020.2972026. ISSN 2169-3536. Bibcode: 2020IEEEA...877642M.
146. ↑ Alzahrani, Naif; Bulusu, Nirupama (2018-06-15). "Block-Supply Chain". Proceedings of the 1st Workshop on Cryptocurrencies and Blockchains for Distributed Systems. CryBlock'18. Munich, Germany: Association for Computing Machinery. pp. 30–35. doi:10.1145/3211933.3211939. ISBN 978-1-4503-5838-5.
147. ↑ Balagurusamy, V. S. K.; Cabral, C.; Coomaraswamy, S.; Delamarche, E.; Dillenberger, D. N.; Dittmann, G.; Friedman, D.; Gökçe, O. et al. (2019-03-01). "Crypto anchors". IBM Journal of Research and Development 63 (2/3): 4:1–4:12. doi:10.1147/JRD.2019.2900651. ISSN 0018-8646. https://ieeexplore.ieee.org/document/8645638. Retrieved 9 January 2021.
148. ↑ Jung, Seung Wook (23 June 2021). "A Novel Authentication System for Artwork Based on Blockchain". in Lee, Robert (eBook). 20th IEEE/ACIS International Summer Semi-Virtual Conference on Computer and Information Science (ICIS 2021). 985. Springer. p. 159. https://books.google.com/books?id=Sbk0EAAAQBAJ&dq=Verisart&pg=PA159. Retrieved 8 July 2023.
149. ↑ Brett, Charles (2018-04-18). "EUIPO Blockathon Challenge 2018 -" (in en-GB). https://www.enterprisetimes.co.uk/2018/04/18/euipo-blockathon-challenge-2018/.
150. ↑ "EUIPO Anti-Counterfeiting Blockathon Forum". https://euipo.europa.eu/ohimportal/en/web/observatory/blockathon.
151. ↑ "PT Industrieel Management". https://privacy.vakmedianet.nl/ptindustrieelmanagement/?ref=https://www.ptindustrieelmanagement.nl/hse/nieuws/2020/06/nen-innoveert-certificatencheck-en-blockchain-1013171?_ga=2.11339894.336094574.1598975931-710406553.1598975931.
152. ↑ "China selects pilot zones, application areas for blockchain project". Reuters. 31 January 2022. https://www.reuters.com/world/china/china-selects-pilot-zones-application-areas-blockchain-project-2022-01-30/.
153. ↑ Šimalčík, Matej (2023). "Rule by Law". in Kironska, Kristina. Contemporary China: a New Superpower?. Routledge. ISBN 978-1-03-239508-1.
154. ↑ Wegner, Peter (March 1996). "Interoperability". ACM Computing Surveys 28: 285–287. doi:10.1145/234313.234424.
155. ↑ Belchior, Rafael; Vasconcelos, André; Guerreiro, Sérgio; Correia, Miguel (May 2020). "A Survey on Blockchain Interoperability: Past, Present, and Future Trends". arXiv:2005.14282 [cs.DC].
156. ↑ Hardjono, T.; Hargreaves, M.; Smith, N. (October 2, 2020). An Interoperability Architecture for Blockchain Gateways (Technical report). IETF. draft-hardjono-blockchain-interop-arch-00.
157. ↑ Hyun Song Shin (June 2018). "Chapter V. Cryptocurrencies: looking beyond the hype". Bank for International Settlements. https://www.bis.org/publ/arpdf/ar2018e5.pdf. "Put in the simplest terms, the quest for decentralised trust has quickly become an environmental disaster."
158. ↑ Janda, Michael (18 June 2018). "Cryptocurrencies like bitcoin cannot replace money, says Bank for International Settlements". ABC (Australia). http://www.abc.net.au/news/2018-06-18/cryptocurrencies-cannot-replace-money-bis/9879448.
159. ↑ Hiltzik, Michael (18 June 2018). "Is this scathing report the death knell for bitcoin?". Los Angeles Times. https://latimes.com/business/hiltzik/la-fi-hiltzik-bitcoin-bank-20180618-story.html.
160. ↑ Ossinger, Joanna (2 February 2022). "Polkadot Has Least Carbon Footprint, Crypto Researcher Says". Bloomberg. https://www.bloomberg.com/news/articles/2022-02-02/polkadot-has-smallest-carbon-footprint-crypto-researcher-says.
161. ↑ Jones, Jonathan Spencer (13 September 2021). "Blockchain proof-of-stake – not all are equal". https://www.smart-energy.com/industry-sectors/new-technology/proof-of-stake-blockchains-not-all-are-equal/.
162. ↑ Criddle, Christina (February 20, 2021) "Bitcoin consumes 'more electricity than Argentina'." BBC News. (Retrieved April 26, 2021.)
163. ↑ Ponciano, Jonathan (March 9, 2021) "Bill Gates Sounds Alarm On Bitcoin's Energy Consumption–Here's Why Crypto Is Bad For Climate Change." Forbes.com. (Retrieved April 26, 2021.)
164. ↑ Rowlatt, Justin (February 27, 2021) "How Bitcoin's vast energy use could burst its bubble." BBC News. (Retrieved April 26, 2021.)
165. ↑ Sorkin, Andrew et al. (March 9, 2021) "Why Bill Gates Is Worried About Bitcoin." New York Times. (Retrieved April 25, 2021.)
166. ↑ Illing, Sean (April 11, 2018). "Why Bitcoin is bullshit, explained by an expert". https://www.vox.com/conversations/2018/4/11/17206018/bitcoin-blockchain-cryptocurrency-weaver.
167. ↑ Weaver, Nicholas (20 April 2018). "Blockchains and Cryptocurrencies: Burn It With Fire". Berkeley School of Information. https://www.youtube.com/watch?v=xCHab0dNnj4.
168. ↑ Köhler, Susanne; Pizzol, Massimo (20 November 2019). "Life Cycle Assessment of Bitcoin Mining". Environmental Science & Technology 53 (23): 13598–13606. doi:10.1021/acs.est.9b05687. PMID 31746188. Bibcode: 2019EnST...5313598K.
169. ↑ Stoll, Christian; Klaaßen, Lena; Gallersdörfer, Ulrich (2019). "The Carbon Footprint of Bitcoin". Joule 3 (7): 1647–1661. doi:10.1016/j.joule.2019.05.012. Bibcode: 2019Joule...3.1647S.
170. ↑ "US lawmakers begin probe into Bitcoin miners' high energy use". Business Standard India. 29 January 2022. https://www.business-standard.com/article/international/us-lawmakers-begin-probe-into-bitcoin-miners-high-energy-use-122012900282_1.html#:~:text=Eight+US+lawmakers+have+come,being+felt+across+the+globe.
171. ↑ Cuen, Leigh (March 21, 2021) "The debate about cryptocurrency and data consumption." TechCrunch. (Retrieved April 26, 2021.)
172. ↑ "The Ethereum Merge: What It Is and Why It Is Important | Insights | Holland & Knight" (in en). https://www.hklaw.com/en/insights/publications/2022/09/the-ethereum-merge-what-it-is-and-why-it-is-important.
173. ↑ Catalini, Christian; Tucker, Catherine E. (11 August 2016). "Seeding the S-Curve? The Role of Early Adopters in Diffusion". SSRN. doi:10.2139/ssrn.2822729. http://www.netinst.org/Catalini_16-02.pdf. Retrieved 22 December 2021.
174. ↑ Arnold, Martin (18 June 2017). "Arnold, M. (2017) "Universities add blockchain to course list", Financial Times: Masters in Finance, Retrieved 26 January 2022.". Financial Times. https://www.ft.com/content/f736b04e-3708-11e7-99bd-13beb0903fa3.
175. ↑ Janssen, Marijn; Weerakkody, Vishanth; Ismagilova, Elvira; Sivarajah, Uthayasankar; Irani, Zahir (2020). "A framework for analysing blockchain technology adoption: Integrating institutional, market and technical factors". International Journal of Information Management (Elsevier) 50: 302–309. doi:10.1016/j.ijinfomgt.2019.08.012. http://resolver.tudelft.nl/uuid:5e48b1c9-f4d3-4f59-9831-529e0d7c91d6.
176. ↑ Koens, Tommy; Poll, Erik (2019), "The Drivers Behind Blockchain Adoption: The Rationality of Irrational Choices", Euro-Par 2018: Parallel Processing Workshops, Lecture Notes in Computer Science, 11339, pp. 535–546, doi:10.1007/978-3-030-10549-5_42, ISBN 978-3-030-10548-8
177. ↑ Li, Jerry (7 April 2020). "Blockchain Technology Adoption: Examining the Fundamental Drivers". Proceedings of the 2020 2nd International Conference on Management Science and Industrial Engineering. Association for Computing Machinery. pp. 253–260. doi:10.1145/3396743.3396750. ISBN 9781450377065. https://doi.org/10.1145/3396743.3396750.
178. ↑ Hsieh, Ying-Ying; Vergne, Jean-Philippe; Anderson, Philip; Lakhani, Karim; Reitzig, Markus (2019-02-12). "Correction to: Bitcoin and the rise of decentralized autonomous organizations". Journal of Organization Design 8 (1): 3. doi:10.1186/s41469-019-0041-1. ISSN 2245-408X.
179. ↑ Felin, Teppo; Lakhani, Karim (2018). "What Problems Will You Solve With Blockchain?". MIT Sloan Management Review.
180. ↑ Beck, Roman; Mueller-Bloch, Christoph; King, John Leslie (2018). "Governance in the Blockchain Economy: A Framework and Research Agenda". Journal of the Association for Information Systems: 1020–1034. doi:10.17705/1jais.00518. https://aisel.aisnet.org/cgi/viewcontent.cgi?article=1835&context=jais.
181. ↑ Popper, Nathaniel (27 June 2018). "What is the Blockchain? Explaining the Tech Behind Cryptocurrencies (Published 2018)". https://www.nytimes.com/2018/06/27/business/dealbook/blockchains-guide-information.html.
182. ↑ Hugh Rooney, Brian Aiken, & Megan Rooney. (2017). Q&A. Is Internal Audit Ready for Blockchain? Technology Innovation Management Review, (10), 41.
183. ↑ Richard C. Kloch, Jr Simon J. Little, Blockchain and Internal Audit Internal Audit Foundation, 2019 ISBN 978-1-63454-065-0
184. ↑ Alexander, A. (2019). The audit, transformed: New advancements in technology are reshaping this core service. Accounting Today, 33(1)
185. ↑ Franco, Pedro (21 October 2014) (in en). Understanding Bitcoin: Cryptography, Engineering and Economics. John Wiley & Sons. p. 74. ISBN 978-1-119-01914-5. https://books.google.com/books?id=erMQBQAAQBAJ&dq=testnet+blockchain&pg=PA74.
186. ↑ Badr, Bellaj; Horrocks, Richard; Wu, Xun (Brian) (30 November 2018) (in en). Blockchain By Example: A developer's guide to creating decentralized applications using Bitcoin, Ethereum, and Hyperledger. Packt Publishing Ltd. p. 19. ISBN 978-1-78847-391-0. https://books.google.com/books?id=ci59DwAAQBAJ&q=testnet free funding faucet.
187. ↑ Hu, Yao-Chieh; Lee, Ting-Ting; Chatzopoulos, Dimitris; Hui, Pan (15 June 2018). "Hierarchical interactions between Ethereum smart contracts across Testnets". Proceedings of the 1st Workshop on Cryptocurrencies and Blockchains for Distributed Systems. Association for Computing Machinery. pp. 7–13. doi:10.1145/3211933.3211935. ISBN 9781450358385. https://doi.org/10.1145/3211933.3211935.
188. ↑ Canellis, David (2018-09-27). "Bitcoin hard fork nightmare becomes reality after testnet splits" (in en). https://thenextweb.com/news/bitcoin-testnet-chainsplit-fork.
189. ↑ "What is a Mainnet?". https://www.investopedia.com/terms/m/mainnet.asp.
190. ↑ "Mainnet Launch: What It Means". https://decrypt.co/resources/what-is-a-mainnet.
191. ↑ Extance, Andy (30 September 2015). "The future of cryptocurrencies: Bitcoin and beyond". Nature 526 (7571): 21–23. doi:10.1038/526021a. ISSN 0028-0836. OCLC 421716612. PMID 26432223. Bibcode: 2015Natur.526...21E.
192. ↑ Ledger (eJournal / eMagazine, 2015). OCLC. OCLC 910895894.
193. ↑ Hertig, Alyssa (15 September 2015). "Introducing Ledger, the First Bitcoin-Only Academic Journal". https://www.vice.com/en/article/introducing-ledger-the-first-bitcoin-only-academic-journal/.
194. ↑ Rizun, Peter R.; Wilmer, Christopher E.; Burley, Richard Ford; Miller, Andrew (2015). "How to Write and Format an Article for Ledger". Ledger 1 (1): 1–12. doi:10.5195/LEDGER.2015.1. ISSN 2379-5980. OCLC 910895894. http://ledger.pitt.edu/ojs/public/journals/1/AuthorGuide.pdf. Retrieved 11 January 2017.
195. ↑ "Why is Git not considered a "block chain"?" (in en). https://stackoverflow.com/questions/46192377/why-is-git-not-considered-a-block-chain.

## Further reading

* Crosby, Michael; Nachiappan; Pattanayak, Pradhan; Verma, Sanjeev; Kalyanaraman, Vignesh (16 October 2015). ﻿BlockChain Technology: Beyond Bitcoin﻿ (Report). Sutardja Center for Entrepreneurship & Technology Technical Report. University of California, Berkeley. http://scet.berkeley.edu/wp-content/uploads/BlockchainPaper.pdf. Retrieved 2017-03-19.
* Jaikaran, Chris (28 February 2018). Blockchain: Background and Policy Issues. Washington, DC: Congressional Research Service. https://crsreports.congress.gov/product/pdf/R/R45116/3. Retrieved 2 December 2018.
* Kakavand, Hossein; De Sevres, Nicolette Kost; Chilton, Bart (12 October 2016). ﻿The Blockchain Revolution: An Analysis of Regulation and Technology Related to Distributed Ledger Technologies﻿ (Report). Luther Systems & DLA Piper.
* Mazonka, Oleg (29 December 2016). "Blockchain: Simple Explanation". http://jrxv.net/x/16/chain.pdf.
* Tapscott, Don; Tapscott, Alex (2016). Blockchain Revolution: How the Technology Behind Bitcoin Is Changing Money, Business and the World. London: Portfolio Penguin. ISBN 978-0-241-23785-4. OCLC 971395169.
* Saito, Kenji; Yamada, Hiroyuki (June 2016). "What's So Different about Blockchain? Blockchain is a Probabilistic State Machine". IEEE 36th International Conference on Distributed Computing Systems Workshops. Nara, Nara, Japan: IEEE. pp. 168–75. doi:10.1109/ICDCSW.2016.28. ISBN 978-1-5090-3686-8.
* Raval, Siraj (2016). Decentralized Applications: Harnessing Bitcoin's Blockchain Technology. Oreilly. ISBN 9781491924549. http://shop.oreilly.com/product/0636920039334.do?sortby=publicationDate. Retrieved 2 May 2017.
* Bashir, Imran (2017). Mastering Blockchain. Packt Publishing, Ltd.. ISBN 978-1-78712-544-5. OCLC 967373845.
* Knirsch, Fabian; Unterweger, Andread; Engel, Dominik (2019). "Implementing a blockchain from scratch: why, how, and what we learned". EURASIP Journal on Information Security 2019. doi:10.1186/s13635-019-0085-3.
* D. Puthal, N. Malik, S. P. Mohanty, E. Kougianos, and G. Das, "Everything you Wanted to Know about the Blockchain", IEEE Consumer Electronics Magazine, Volume 7, Issue 4, July 2018, pp. 6–14.
* David L. Portilla, David J. Kappos, Minh Van Ngo, Sasha Rosenthal-Larrea, John D. Buretta and Christopher K. Fargo, Cravath, Swaine & Moore LLP, "Blockchain in the Banking Sector: A Review of the Landscape and Opportunities", Harvard Law School of Corporate Governance, posted on Friday, January 28, 2022

## External links

* v
* t
* e

Cryptocurrencies

Technology|

* Blockchain
* Cryptocurrency tumbler
* Cryptocurrency exchange
* Cryptocurrency wallet
* Cryptographic hash function
* Distributed ledger
* Fork
* Lightning Network
* Smart contract

Consensus mechanisms|

* Proof of authority
* Proof of space
* Proof of stake
* Proof of work

Proof of work currencies|

| SHA-256-based|

* Bitcoin
* Bitcoin Cash
* Counterparty
* MazaCoin
* Namecoin
* Peercoin
* Titcoin

|

Ethash-based|

* Ethereum
* Ethereum Classic

Scrypt-based|

* Auroracoin
* Bitconnect
* Bitcoin Gold
* Coinye
* Dogecoin
* Litecoin
* PotCoin

Equihash-based|

* Zcash

CryptoNote-based|

* Monero

X11-based|

* Dash
* Petro

Lyra2-based|

* Taler

Other|

* Primecoin
* Verge
* Vertcoin
* Zcoin

Proof of stake currencies|

* Gridcoin
* EOS.IO
* Nxt
* Steem
* Tezos

ERC-20 tokens|

* Aragon
* Augur
* Aventus
* Basic Attention Token
* Centra
* Kin
* KodakCoin
* Minds
* Power Ledger

Other currencies|

* BitShares
* Filecoin
* Libra
* NEM
* NEO
* Ripple
* Stellar
* Tether

Related topics|

* Airdrop
* BitLicense
* Blockchain game
* Complementary currency
* Crypto-anarchism
* Cryptocurrency bubble (2018 cryptocurrency crash)
* Digital currency
* Double-spending
* Initial coin offering
* Initial exchange offering
* Initiative Q
* List of cryptocurrencies
* Stablecoin
* Token money
* Virtual currency

* Category
* Commons
* List

* v
* t
* e

Bitcoin

* History
* Economics
* Legal status

Groups|

* List of bitcoin companies
* List of bitcoin organizations
* List of people in blockchain technology

Note: This topic belongs to "Money" portal

Technologies|

* Base58
* Bitcoin network
* Blockchain
* Colored coins
* Cryptocurrency
* Bitcoin ATM
* ECDSA
* Lightning Network
* P2P
* Proof of work
* SegWit
* SHA-2

Software client|

* Bitcoin Core

Forks|

| Client|

* Bitcoin XT
* Bitcoin Classic
* Bitcoin Unlimited

|

Currency|

* Bitcoin Cash
* Bitcoin Gold

Exchanges|

* Binance
* Bitcoin Center NYC
* Bitfinex
* bitFlyer
* Bithumb
* BitMEX
* Bitstamp
* Bittrex
* BTCC
* CEX.io
* Coinbase
* Coincheck
* CoinCorner
* Coinfloor
* Coins.ph
* Gemini
* Huobi
* Kraken
* LocalBitcoins
* OKEx
* ShapeShift
* Upbit

| Defunct|

* BTC-e
* Cryptopia
* Mt. Gox
* QuadrigaCX

|

* Book
* Category
* Commons

* v
* t
* e

Database management systems

Types|

* Object-oriented
* comparison
* Relational
* comparison
* Document-oriented
* Graph
* NoSQL
* NewSQL

Concepts|

* Database
* ACID
* Armstrong's axioms
* CAP theorem
* CRUD
* Null
* Candidate key
* Foreign key
* Superkey
* Surrogate key
* Unique key

Objects|

* Relation
* table
* column
* row
* View
* Transaction
* Transaction log
* Trigger
* Index
* Stored procedure
* Cursor
* Partition

Components|

* Concurrency control
* Data dictionary
* JDBC
* XQJ
* ODBC
* Query language
* Query optimizer
* Query rewriting system
* Query plan

Functions|

* Administration
* Query optimization
* Replication

Related topics|

* Database models
* Database normalization
* Database storage
* Distributed database
* Federated database system
* Referential integrity
* Relational algebra
* Relational calculus
* Relational database
* Relational model
* Object-relational database
* Transaction processing

0.00

(0 votes)

Original source: https://en.wikipedia.org/wiki/Blockchain. Read more

|

Retrieved from "https://handwiki.org/wiki/index.php?title=Finance:Blockchain&oldid=3967976"
*[v]: View this template
*[t]: Discuss this template
*[e]: Edit this template