A Review on the Application of Blockchain to the Next Generation of Cybersecure Industry 4.0 Smart Factories

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

There is not much research on industrial blockchain-based robots and cobots.

“There is not much research on industrial blockchain-based robots and cobots”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

There is not much research on the application of blockchain to IAR/IVR applications.

“There is not much research on the application of blockchain to IAR/IVR applications”

Probably not a substantial claim: may not pass S2 (checkable), S4 (based).

Most of the previous challenges can be faced by a blockchain, which acts as a ledger that stores all the performed transactions.

“Most of the previous challenges can be faced by a blockchain, which acts as a ledger that stores all the performed transactions.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

Public blockchains can be useful in certain industrial scenarios where a high level of transparency is necessary or where massive consumer device interaction is required.

“Public blockchains can be useful in certain industrial scenarios where a high level of transparency is necessary or where massive consumer device interaction is required.”

Classified as probably not a substantial claim.

Application decentralization is desirable especially for Industry 4.0 applications with medium and large user and computational loads, since they rely on expensive centralized servers that are costly to deploy and maintain.

“Application decentralization.It is desirable especially for Industry 4.0 applications with medium and large user and computational loads, since they rely on expensive centralized servers that are also costly to deploy and maintain [9], [10].”

• cites [9] sourceNot checked yet

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• AssumptionRests on an assumption: Many industrial companies pay middlemen for outsourcing centralized solutions.

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Two key costs may be reduced by blockchain: verification and networking costs.

“Two key costs may be reduced by blockchain: verification and networking costs.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

IOTA's architecture (Tangle) allows it to be efficient, scalable and lightweight.

“IOTA's architecture (called Tangle) allows it to be efficient, scalable and lightweight.”

May combine two claims.

This is essential in critical infrastructures and defense, whose data have to be stored through trusted service providers, especially in countries where data privacy and security are not guaranteed.

“This is essential in the case of critical infrastructures [34], [35] and defense [36], whose data, due to legal and privacy concerns (e.g., certain defense data are considered strategic and therefore classified), have to be stored through trusted service providers, especially in countries where data privacy and security are not guaranteed [37].”

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Probably not a substantial claim: may not pass S2 (checkable), S4 (based). May combine two claims.

Blockchain can bring many benefits to multiple industrial fields and can become a useful tool for Industry 4.0 applications.

“Blockchain can bring many benefits to multiple industrial fields and it can also become a very useful tool for Industry 4.0 applications.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

Tangle does not use blocks, requires no miners, provides high-speed transactions with no network fees, and allows for seemingly infinite scalability.

“Tangle does not use blocks, it requires no miners, it provides high-speed transactions with no network fees, and allows for seemingly infinite scalability.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Blockchain may add value to different fields and evolve the existing Internet, enabling the transformation from the 'Internet of Information' to the 'Internet of Value' and the creation of a true peer-to-peer sharing economy.

“Blockchain may add value to different fields and evolve the existing Internet, enabling the transformation from the 'Internet of Information' to the 'Internet of Value' and the creation of a true peer-to-peer sharing economy [8].”

• cites [8] sourceNot checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Practical implementations of consortium blockchains can be found for financial institutions, for the energy sector and for the insurance industry.

“Practical implementations of consortium blockchains can be found for financial institutions [41], for the energy sector [42] and for the insurance industry [43].”

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Probably not a substantial claim: may not pass S3 (load-bearing).

Tangle is not as proven and tested as blockchain, since it has not had as many users and developers.

“The technology is not as proven and tested as blockchain, since it has not had as much users and developers.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

The existence of a payment system may be used to automate many systematic tasks and thus accelerate transactions among parties.

“Moreover, the existence of a payment system may be used to automate many systematic tasks and thus accelerate transactions among parties.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

Such features have been traditionally provided by databases, whose security is essential, especially when they are accessed through the Internet and thus exposed publicly to attacks on their availability or on data privacy.

“It is worth mentioning that such features have been traditionally provided by databases, whose security is essential, especially when they are accessed through the Internet and thus exposed publicly to attacks on their availability or on the data privacy.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The validation process is essential because it provides a decentralized solution to the Byzantine Generals' Problem.

“Such a validation process is essential, since it provides a decentralized solution to the Byzantine Generals' Problem [13] that shows how to reach an agreement among different entities (generals) to do something (a battle plan) when such entities do not trust each other and when they only exchange messages that may be malicious (i.e., they may come from traitors).”

• cites [13] sourceNot checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

In private networks, traditional databases usually provide a fast and powerful tool for many applications.

“For instance, in private networks, traditional databases usually provide a fast and powerful tool for many applications.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

Traditional payment systems often carry two drawbacks: they usually involve higher transaction fees than public blockchains and they have to be trusted almost blindly.

“It is possible to carry out payments through traditional payment systems, but they often carry two drawbacks: they usually involve higher transaction fees than public blockchains and they have to be trusted almost blindly, without questioning their security, ethics or internal policies.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Trust and transparency are reasons to create public transaction logs.

“Trust and transparency are also the reasons to create public transaction logs.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Consortium or federated blockchains restrict user access to the network and the actions performed by participants, and the consensus algorithm is usually run by a pre-selected group of nodes, which increases transaction privacy and accelerates transaction validation.

“They restrict user access to the network and the actions performed by the participants.In fact, the consensus algorithm is usually run by a pre-selected group of nodes, what increases transaction privacy and accelerates transaction validation.”

Probably not a substantial claim: may not pass S4 (based).

Blockchain can help automate industrial processes that involve multiple companies.

“Since blockchain can help to automate industrial processes that involve multiple companies (examples are given later in Section III), it is important to define the concept of smart contract”

Probably not a substantial claim: may not pass S3 (load-bearing).

Blockchain is not always the optimum choice to solve every problem.

“However, blockchain is not always the optimum choice to solve every problem.”

Probably not a substantial claim: may not pass S3 (load-bearing).

There are already other technologies that serve the same purpose as blockchain (to create a trustless decentralized network that tackles the double-spending problem), which can be convenient for many Industry 4.0 applications, especially for IIoT applications or micro-payments.

“Moreover, there are already other technologies that serve the same purpose as blockchain (i.e., to create a trustless decentralized network that tackles the double-spending problem), which can be convenient for many Industry 4.0 applications, especially for IIoT applications or micro-payments.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Another relevant feature that may be required by an Industry 4.0 application is the need for using P2P communications to exchange data among the different parties involved in industrial processes.

“Another relevant feature that may be required by an Industry 4.0 application is the need for using P2P communications to exchange data among the different parties involved in the industrial processes.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

IOTA is currently the most popular DAG-based project in the industrial field.

“IOTA is currently the most popular DAG-based project in the industrial field.”

May combine two claims.

The most common reason to justify blockchain is the lack of trust in the organization that manages the infrastructure or some privacy requirements specified by a client.

“The most common reason is the lack of trust in the organization that manages the infrastructure or some privacy requirements specified by a client [33].”

• cites [33] sourceNot checked yet

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May combine two claims.

Not every Industry 4.0 technology requires decentralization, but some may benefit from it, especially when there is a centralized system that is not trusted.

“Not every Industry 4.0 technology requires decentralization, but some may benefit from it, especially when there is a centralized system that is not trusted.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Blockchain can be useful when decentralization is needed in an application.

“First, blockchain can be useful when decentralization is needed in an application (i.e., when such an application is enhanced by being run on a P2P network of computers instead of on a single machine).”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

Open-source code can suffer from bugs and exploits but, since it is verified by many developers, it is less susceptible to malicious modifications.

“Nonetheless, it should be emphasized that open-source code can also suffer from bugs and exploits but, since it is verified by many developers, it is less susceptible to malicious modifications.”

• AssumptionRests on an assumption: Many industrial companies depend on closed-source code, which increases the lack of trust because it is not transparent on how the code works.

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

If there is trust among the different entities, blockchain is not needed.

“Nonetheless, if there is trust among the different entities, blockchain is not needed.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

IOTA can communicate with blockchains, which allows for future collaboration between them.

“In addition, IOTA can communicate with blockchains, which allows for future collaboration between them.”

Probably not a substantial claim: may not pass S3 (load-bearing).

There exist different types of blockchains depending on how users interact with them and how data are managed or accessed.

“There exist different types of blockchains depending on how users interact with them and how data are managed/accessed [18].”

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Probably not a substantial claim: may not pass S3 (load-bearing).

The concepts behind Industry 4.0 were first defined by the German government in 2011.

“The concepts behind Industry 4.0 are said to be first defined by the German government in 2011 [2], [3].”

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Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

Tangle cannot provide true DApp functionality or Turing-complete solutions.

“Tangle cannot provide true DApp functionality or Turing-complete solutions.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Blockchain originated from Bitcoin and allows creating decentralized applications (DApps) able to track and store transactions performed by a large amount of simultaneous users and devices.

“decentralized applications (DApps) able to track and store transactions performed by a large amount of simultaneous users and devices.”

• cites [7]Not checked yet

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Probably not a substantial claim: may not pass S4 (based).

Blockchain can add trust, security, and decentralization to different industrial fields.

“One of such technologies is blockchain, which is able to add trust, security, and decentralization to different industrial fields.”

May combine two claims.

Such IIoT nodes commonly route their data through gateways by using non-P2P protocols like MQTT or by making use of a fog or edge computing infrastructure.

“Due to this reason, such a kind of IIoT nodes commonly route their data through gateways by using non-P2P protocols like MQTT [30] or by making use of a fog [31] or edge computing infrastructure [32].”

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Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Industry 4.0 represents the next step in the evolution of traditional factories towards smart factories, designed to be more efficient in resource management and highly flexible to adapt to changing production requirements.

“Industry 4.0 represents the next step on the evolution of traditional factories towards actual smart factories, which are designed to be more efficient in terms of resource management and to be highly flexible to adapt to ever-changing production requirements [1].”

• cites [1]Not checked yet

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Classified as probably not a substantial claim. May combine two claims.

Since there are good alternatives provided by server farms or clouds, there have to be other factors to justify the use of a blockchain.

“Since there are good alternatives provided by server farms or clouds, there have to be other factors to justify the use of a blockchain.”

Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing), S4 (based).

Trust is necessary when payments have to be performed.

“Trust is necessary when payments have to be performed.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

Tangle can be less secure, for example it can be compromised with a 34-percent attack, as opposed to the 51-percent or majority attack of blockchain.

“It can be less secure (e.g., it can be compromised with a 34-percent attack, as opposed to the 51-percent or majority attack of blockchain).”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Due to the existence of a single owner, private blockchains might not be actually considered decentralized, operating more like a close secure distributed database, which may be desirable in certain industrial environments where blockchain participants are well-known or where audits need to be performed.

“It is important to note that, due to the existence of a single owner, private blockchains might not be actually considered decentralized, operating more like a close secure distributed database, which may be desirable in certain industrial environments where blockchain participants are well-known or where audits need to performed.”

Probably not a substantial claim: may not pass S3 (load-bearing).

A credit-based payment scheme can support fast and frequent secured energy trading.

“An example of application is a credit-based payment scheme to support fast and frequent secured energy trading [66].”

• cites [66]Not checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims. The quote only partly states this claim.

Smart contracts can accelerate certain bureaucratic tasks and a blockchain can be used to carry out interactions for dynamic integration of design and engineering stages.

“Thus, smart contracts can accelerate certain bureaucratic tasks and a blockchain can be used to carry out the mentioned interactions.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

A blockchain can act as an information exchange hub whose users, which are technology independent, only have to implement the appropriate blockchain client functionality.

“A blockchain can act as an information exchange hub whose users, which are technology independent, only have to implement the appropriate blockchain client functionality.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The horizontal integration required in manufacturing and supply chain processes is a good target for blockchain-based enhancements thanks to decentralized transactions and data management capabilities.

“The horizontal integration required in manufacturing and supply chain processes is a good target for blockchain-based enhancements thanks to decentralized transactions and its data management capabilities.”

May combine two claims.

Blockchain can provide integrity service frameworks to avoid trusting third parties, but such systems still have to evolve.

“Blockchain can provide integrity service frameworks to avoid trusting third parties [72], but such a kind of systems still has to evolve.”

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Probably not a substantial claim: may not pass S3 (load-bearing).

The final cost of deploying a blockchain includes software integration costs plus the cost of time required to understand underlying business processes and define precise and flexible smart contracts.

“the final cost of deploying a blockchain not only includes the costs related to software integration, but also the cost of the time required to understand the underlying business processes and to define precise and flexible smart contracts”

• cites [85]Not checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing).

Due to the progress of quantum computing on breaking traditional asymmetric cryptographic algorithms, post-quantum approaches should be considered.

“Moreover, due to the progress of quantum computing on breaking traditional asymmetric cryptographic algorithms, post-quantum approaches should be considered [71].”

• cites [71]Not checked yet

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Probably not a substantial claim: may not pass S4 (based).

Blockchain data are distributed among peers, so the disruption of the communications of one or more participants should not affect the access to the data.

“Blockchain data are distributed among peers, so the disruption of the communications of one or more participants should not affect the access to the data.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Some researchers propose the use of permissioned blockchains to manage multiple IIoT node identification, while others suggest using multichains where only a subset of participants can monitor blockchain activities.

“To tackle this issue some researchers propose the use of permissioned blockchains, that can manage multiple IIoT node identification [69], while others suggest using multichains [48] (where only a subset of the participants can monitor blockchain activities).”

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Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Blockchains are continuously growing as IIoT devices perform transactions, implying the use of more powerful miners.

“Blockchains are continuously growing as IIoT devices perform transactions, what implies the use of more powerful miners.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

The biggest challenge for hardware oracles is to report readings without sacrificing data security and to guarantee that such readings correspond to a specific physical process.

“The biggest challenge for these hardware oracles is to report readings without sacrificing data security and to guarantee that such readings correspond to a specific physical process.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Such entities differ from cryptocurrencies in certain aspects, like the use of power constraint devices that have to interact with the blockchain either directly or indirectly.

“Nonetheless, such entities differ from cryptocurrencies in certain aspects, like the use of power constraint devices (e.g., IIoT sensors, AR glasses, battery-operated machinery) that have to interact with the blockchain either directly (by implementing a low-consumption implementation of a blockchain client) or indirectly (through an intermediate gateway).”

Probably not a substantial claim: may not pass S3 (load-bearing).

Mining hardware evolved remarkably in the last years until the development of dedicated Application-Specific Integrated Circuits (ASICs).

“mining hardware evolved remarkably in the last years until the development of dedicated Application-Specific Integrated Circuits (ASICs) [82]”

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May combine two claims.

One feature of a technology can be improved by using blockchain, but the same feature may still be a challenge for another technology.

“Such a situation is illustrated in Figures 4 and 5, where it can also be observed that one feature of a technology can be improved by using blockchain, but the same feature may be still a challenge for another”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Industry 4.0 demands higher integration levels because MES, PLM, ERP and IoT platforms may not be shared with other industrial partners or clients, requiring additional expensive integrations.

“Industry 4.0 demands higher integration levels, since the mentioned platforms may not be shared with other industrial partners or clients (thus requiring additional integrations, which are usually very expensive).”

• AssumptionRests on an assumption: Horizontal and vertical integration are essential to automate data exchanges inside factories and to communicate with suppliers and clients.

Probably not a substantial claim: may not pass S3 (load-bearing).

Other authors studied the advantages that an IoT-compliant blockchain can bring to the performance of the IEEE P1931.1 Real-Time Onsite Operations Facilitation (ROOF) standard.

“Other authors studied the advantages that an IoT-compliant blockchain can bring to the performance of the IEEE P1931.1 Real-Time Onsite Operations Facilitation (ROOF) standard [67].”

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Probably not a substantial claim: may not pass S3 (load-bearing).

Smart contract conditions are based on data that depends on external services called oracles.

“Smart contract conditions are based on data that depends on external services that take data from the real world and store them into the blockchain (or vice versa).Such services are referred to as oracles.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Blockchains demand infrastructure to support decentralized storage and mining.

“Blockchains demand infrastructure to support decentralized storage and mining.”

May combine two claims.

Some authors have already proposed alternatives like mini-blockchains, which help to reduce the number of peer updates while lowering the computational requirements of a full node.

“For instance, some authors have already proposed alternatives like mini-blockchains [76], which help to reduce the number of peer updates while lowering the computational requirements of a full node.”

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Probably not a substantial claim: may not pass S3 (load-bearing).

Bitcoin transaction latency follows a Poisson distribution with a 10-minute mean.

“Bitcoin transaction latency follows a Poisson distribution with a 10-minute mean [7]”

• cites [7]Not checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

By default, all IIoT devices are identified by their public key or its hash, so their anonymity is not guaranteed in case it is required.

“By default, all IIoT devices are identified by their public key (or its hash), so their anonymity is not guaranteed in case it is required”

May combine two claims.

Industry 4.0 technologies can benefit from the use of a blockchain, but its application also currently supposes a challenge in diverse aspects.

“Industry 4.0 technologies can benefit from the use of a blockchain, but its application also currently supposes a challenge in diverse aspects.”

Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing). May combine two claims.

RSA-based cryptography may not be the most appropriate for certain resource-constraint IIoT devices, so other asymmetric cryptographic mechanisms should be studied.

“RSA-based cryptography may not be the most appropriate for certain resource-constraint IIoT devices, so other asymmetric cryptographic mechanisms should be studied [70].”

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Classified as probably not a substantial claim.

A blockchain and smart contracts may become the horizontal integration mechanisms for the entities involved in Industry 4.0 processes, either for performing economic or simple data transactions.

“Such a level of integration involves the deployment of low-latency and flexible communication networks, so a blockchain and smart contracts may become the horizontal integration mechanisms for the entities involved in Industry 4.0 processes, either for performing economic or simple data transactions.”

Classified as probably not a substantial claim. May combine two claims.

Since certain IIoT devices rely on batteries to operate, it is necessary to minimize power consumption.

“Since certain IIoT devices rely on batteries to operate, it is necessary to minimize power consumption.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Different consensus mechanisms have been proposed to develop alternatives greener than traditional PoW schemes, such as Proof-of-Stake and Proof-of-Space, but further research is required.

“In the case of mining, different consensus mechanisms have been proposed to develop alternatives greener than traditional PoW schemes (e.g., Proofof-Stake, Proof-of-Space [75]), but further research is required.”

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Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Energy efficient hashing algorithms can help extend the battery life of IIoT devices; although SHA-256 is probably the most popular hash algorithm due to Bitcoin, recent alternatives like Scrypt or X11 are faster, so they may reduce mining energy consumption.

“It is also worth mentioning that energy efficient hashing algorithms can help to extend the battery life of IIoT devices: although SHA-256 is probably the most popular hash algorithm due to Bitcoin, recent alternatives like Scrypt [77] or X11 [78] are faster, so they may reduce mining energy consumption.”

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Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Consensus-based oracles combine different oracles to determine the outcome of an event, and prediction markets like Augur and Gnosis use a rating system for oracles to confirm future outcomes and avoid market manipulation.

“Consensus-based oracles combine different oracles to determine the outcome of an event.For instance, prediction markets like Augur [52] and Gnosis [53] make use of a rating system for oracles to confirm future outcomes and to avoid market manipulation.”

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Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

In practice, it is recommended to wait about an hour for confirmation of a Bitcoin transaction because five or six blocks need to be added to the chain before confirmation.

“it is recommended to wait about an hour for the confirmation of the transaction (this occurs because five or six blocks need to be added to the chain before their confirmation)”

• cites [7]Not checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Transaction recording helps keep track of goods and provides transparency to third parties.

“Transaction recording also helps to keep track of the goods and also provides transparency to third parties.”

May combine two claims.

Current resource-constraint IIoT nodes are not able to cope with PoW or mining tasks in general, so they usually rely on intermediate gateways that act as proxies with the blockchain.

“In addition, it must be noted that, despite possible energy consumption optimizations, current resource-constraint IIoT nodes are not able to cope with PoW or mining tasks in general, so they usually rely on intermediate gateways that act as proxies with the blockchain.”

May combine two claims.

Blockchain provides traceability, transparency, tamper-proofness, and flexibility to changing environments and regulations.

“Blockchain provides such features and also adds flexibility to changing environments and regulations.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Although blockchain provides relevant benefits, its adoption is a challenge for traditional industries due to its learning curve and integration costs.

“although a blockchain provides relevant benefits, its adoption is a challenge for traditional industries due to its learning curve and the integration costs”

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Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

When an organization sets an identity provider to authorize access to IIoT devices and other participants to the IIoT ecosystem, such a provider is also usually able to block their access.

“It is important to note that when an organization sets an identity provider to authorize access to IIoT devices and other participants to the IIoT ecosystem, such a provider is also usually able to block their access.”

May combine two claims.

Mixing techniques increase IIoT data privacy, but in some cases they can be de-anonymized.

“Mixing techniques increase IIoT data privacy, but in some cases they can be de-anonymized [68].”

• cites [68]Not checked yet

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May combine two claims.

Blockchain can give public or semi-public access to IIoT data, which is important for some industries whose transparency is considered essential by certain participants in order to trust a company.

“Give public or semi-public access to IIoT data.This is important for some industries whose transparency is considered essential by certain participants (e.g., governments, supervisors, stakeholders) in order to trust a company.”

Classified as probably not a substantial claim. May combine two claims.

It is critical for IIoT systems to guarantee that the information collected from IIoT devices has not been modified, since incorrect or malicious data can alter essential parts of an industrial system.

“It is critical for IIoT systems to guarantee that the information collected from IIoT devices has not been modified, since incorrect or malicious data can alter essential parts of an industrial system.”

May combine two claims.

Blockchain can provide enhanced Simulation-as-a-Service and decentralized co-simulation functionality.

“Providing enhanced Simulation-as-a-Service and decentralized co-simulation functionality [154].”

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May combine two claims.

Blockchain can improve data reliability by creating trust among involved entities, securing shared data and providing data timestamping.

“Blockchain can improve data reliability by creating trust among the involved entities [96], securing the shared data and providing data timestamping [19].”

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Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Since traceability can be preserved throughout the life of a product, a blockchain can be used as a tool to foster responsible consumption.

“Since traceability can be preserved throughout the life of a product, a blockchain can be used as a tool to foster responsible consumption.”

• cites [86] sourceNot checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing).

Blockchain can be used to improve cybersecurity in data sharing of sensitive data of military, law enforcement or public safety forces in the battlefield.

“blockchain can be used to improve cybersecurity in the data sharing of sensitive data of the military, law enforcement or public safety forces in the battlefield”

May combine two claims.

Most blockchain technologies require certain time to reach consensus and confirm transactions, which may be a problem in many ICPSs that have to react in real or quasi-real time.

“Most blockchain technologies require certain time to reach consensus and confirm transactions, what may be a problem in many ICPSs that have to react in real or quasi-real time to the collected data and events.”

May combine two claims.

A blockchain can help additive manufacturing by improving transparency and validating the origin of manufacturing files.

“A blockchain can help by improving transparency and validating the origin of the manufacturing files [143].”

• cites [143] sourceNot checked yet

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May combine two claims.

Smart contracts can standardize and automate data circulation, making it transparent to third parties.

“smart contracts can be really helpful, since they are able to standardize and automate data circulation, making it transparent to third parties.”

May combine two claims.

A blockchain may allow decreasing delivery time and optimizing stock management by distributing work offers from industrial consumers to producers.

“The use of a blockchain may allow for decreasing delivery time and optimizing stock management by distributing work offers from industrial consumers to producers [137]”

• cites [137] sourceNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing).

Smart contracts can create licensing agreements so that the licensee can only print a specific amount of copies of the licensed component.

“smart contracts to create licensing agreements so that the licensee can only print a specific amount of copies of the licensed component”

• cites [144] sourceNot checked yet

  Not checked in the free run.

May combine two claims.

Blockchains, like other types of distributed systems, are prone to Sybil attacks, which can alter the proper behavior of the system.

“blockchains, like other types of distributed systems, are prone to Sybil attacks [150], which can alter the proper behavior of the system.”

• cites [150] sourceNot checked yet

  Not checked in the free run.

May combine two claims.

The use of blockchain-based IAR/IVR devices involves challenges because they are usually battery operated and restricted in computing power, suffering from similar problems to IIoT hardware.

“they are usually battery operated and, although they can embed really powerful Graphics Processing Units (GPUs), they are restricted in terms of computing power, so they suffer from similar problems to IIoT hardware.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Blockchain can be used to negotiate automatically the reserve of resources offered by a 5G infrastructure provider, allowing mobile network and service operators to perform reservations on-demand, easily and dynamically.

“the authors suggest using a blockchain to negotiate automatically the reserve of resources offered by a 5G infrastructure provider”

• cites [87] sourceNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing).

More computing nodes are not necessarily able to cope with higher workloads in a blockchain-based ICPS because transactions need to be processed serially.

“more computing nodes are not necessarily able to cope with higher workloads, since transactions need to be processed serially”

• cites [93]Not checked yet

  Not checked in the free run.

May combine two claims.

Trade in additive manufacturing can become automated through smart contracts, giving transparency to third parties.

“such a trade can become automated through smart contracts [144], also giving transparency to third parties”

• cites [144] sourceNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing).

Certain manufacturers proposed relying on a blockchain to decentralize an AR/VR application ecosystem, giving developers freedom to create their own storefronts and marketplaces.

“Certain manufacturers proposed relying on a blockchain to decentralize such an ecosystem so that to give developers freedom for creating their own storefronts and marketplaces.”

• cites [109] sourceNot checked yet

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• cites [110]Not checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

IIoT devices whose data are collected by ICPS are often limited in computing power, so they may not be able to use certain cryptographic mechanisms.

“The IIoT devices whose data are collected by ICPS are often limited in terms of computing power, so they may not be able to make use of certain cryptographic mechanisms.”

Probably not a substantial claim: may not pass S3 (load-bearing).

An ICPS would benefit from the use of a blockchain to coordinate local real-time processes.

“an ICPS would benefit from the use of a blockchain to, for instance, coordinate local real-time processes”

• cites [93]Not checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

AR and VR are helpful in industrial design processes, manufacturing certain goods, and maintaining specific industrial components.

“to be helpful in industrial design processes [98], [99], when manufacturing certain goods [100]- [103] or for maintaining specific industrial components [104], [105].”

• cites [98]Not checked yet

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• cites [99]Not checked yet

  Not checked in the free run.

• cites [100]-[103]Not checked yet

  Not checked in the free run.

May combine two claims.

Although blockchain technology can increase Industry 4.0 application security, its use entails certain security issues that should be identified and addressed.

“although blockchain technology can increase Industry 4.0 application security, its use entails certain security issues that should be identified and addressed [151].”

• cites [151] sourceNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing).

Blockchain-based systems are designed as distributed systems that can complement cloud computing deployments in certain aspects.

“blockchain-based systems are designed as distributed systems that can complement cloud computing deployments in certain aspects.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Both AR and VR proved to increase productivity.

“they proved to increase productivity [97]”

• cites [97] sourceNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing).

The combination of blockchain with IPFS can ease version control and distribution of digital assets in a secured manner.

“the combination of blockchain with the storage and peerto-peer properties of Interplanetary File System (IPFS) can ease version control and the process of distributing the digital assets in a secured manner.”

May combine two claims.

Blockchain can enhance Big Data and Data Analytics when facing three major issues: data collection, data trustworthiness and automated reliable data circulation.

“Blockchain can enhance Big Data and Data Analytics when facing three major issues [94]: data collection, data trustworthiness and automated reliable data circulation.”

• cites [94] sourceNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing).

A blockchain can distribute computing calculations among multiple peers to accelerate the 3D printing process.

“a blockchain that can distribute the computing calculations among multiple peers (maybe involving economic incentives) in order to accelerate the 3D printing process.”

Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

Due to the decentralized nature of an ICPS and its need for data redundancy, blockchain is a good complement for such systems.

“Due to the decentralized nature of an ICPS and its need for data redundancy, it seems that blockchain is a good complement for such a kind of systems.”

May combine two claims.

Since data on the blockchain are distributed, although one participant may be under attack, the information can be available through other nodes, thus guaranteeing data availability.

“since the data on the blockchain are distributed, although one participant may be under attack, the information can be available through other nodes, thus guaranteeing data availability.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

The architectures selected to support blockchain-based Industry 4.0 applications would have to withstand the significant amount of traffic that such applications usually generate.

“The architectures selected to support blockchain-based Industry 4.0 applications would have to withstand the significant amount of traffic that such applications usually generate.”

May combine two claims.

Most blockchains use public-key cryptosystems based on ECC, which is generally lighter than RSA at the same security level, but such cryptography is still power hungry.

“most blockchains make use of public-key cryptosystems based on Elliptic Curve Cryptography (ECC), which is generally lighter that traditional Rivest-Shamir Addleman (RSA) when compared at the same security level [156], such a kind of cryptography is still power hungry.”

• cites [156] sourceNot checked yet

  Not checked in the free run.

The quote only partly states this claim.

A blockchain can improve data availability for AR/VR applications by providing decentralization.

“A blockchain can also improve data availability.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Serialization of transactions creates a performance bottleneck and affects scalability in a blockchain-based ICPS.

“the serialization of transactions, which creates a performance bottleneck and that affects scalability”

• cites [93]Not checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Fog and edge computing are based on offloading part of the processing from the cloud to the edge of the network, which reduces latency response.

“fog [132]- [134] and edge computing [135], which is based on offloading part of the processing from the cloud to the edge of the network, what also reduces latency response.”

• cites [132]-[134]Not checked yet

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• cites [135] sourceNot checked yet

  Not checked in the free run.

May combine two claims.

Private and consortium blockchains can restrict user access, reducing the number of possible attackers.

“private and consortium blockchains can restrict user access, reducing the number of possible attackers.”

May combine two claims.

A blockchain-based consumer's supply chain enables creation of a digital identity for products, limiting counterfeiting and preserving ownership.

“It enables the creation of a digital identity for products, thus limiting counterfeiting and preserving ownership.”

• cites [86] sourceNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing).

In a blockchain-based edge computing application, blockchain is used to avoid allocating the same frequency to multiple network providers, preventing resource double-spending.

“the blockchain is used to avoid allocating the same frequency to multiple network providers (i.e., prevent resource doublespending)”

• cites [136] sourceNot checked yet

  Not checked in the free run.

May combine two claims.

Blockchain-based robots and vehicles can collaborate and do business among them and with third parties in a completely autonomous way.

“blockchain-based robots and vehicles can collaborate and do business among them and with third parties in a completely autonomous way.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

A blockchain needs a relevant amount of storage to keep all transactions, which may be a problem for certain resource-constraint nodes that send data to an ICPS.

“A blockchain needs a relevant amount of storage to keep all the transactions, what may be a problem for certain resource-constraint nodes that send data to an ICPS.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The European Union launched in February 2018 its Blockchain observatory and forum, whose main objective is to map key initiatives, monitor developments and develop common actions at an EU level.

“the European Union launched in February 2018 its Blockchain observatory and forum, whose main objective is to map key initiatives, monitor developments and develop common actions at an EU level [168].”

• cites [168] sourceNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

Energy efficiency, throughput and latency issues described for IIoT and CPSs can be extrapolated to other blockchain applications.

“These issues were previously described in relation to IIoT and CPSs, but they can be extrapolated to other blockchain applications.”

Probably not a substantial claim: may not pass S3 (load-bearing).

μRaiden enables micropayments through unidirectional payment channels.

“a simplified version of this solution called µRaiden [166] enables to make micropayments through unidirectional payment channels.”

• cites [166] sourceNot checked yet

  Not checked in the free run.

May combine two claims.

It is not necessary to use the most egalitarian consensus mechanism because in public blockchains such a mechanism would be prone to Sybil attacks and a single entity would be able to control the whole blockchain.

“it is not necessary to use the most egalitarian (and idealistic) consensus mechanism, which would consist in giving to all the miners the same weight when voting, since in certain blockchains (e.g., public blockchains), such a mechanism would be prone to Sybil attacks and then a single entity would be able to control the whole blockchain.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Mining, although useful in public blockchains, is not indispensable for every scenario, so the computational effort and energy consumed by the consensus algorithm can be drastically reduced.

“mining, although it is very useful in public blockchains, it is not indispensable for every scenario, so the computational effort and energy consumed by the consensus algorithm can be drastically reduced.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Interoperability among blockchain solutions is necessary in many scenarios to achieve seamless integration.

“interoperability among them is necessary in many scenarios in order to achieve a seamless integration.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Ethereum is making steady progress towards scalability with on-chain sharding and off-chain Raiden and Plasma.

“Ethereum is making a steady progress towards scalability with the development of on-chain solutions like sharding [162] or off-chain ones like Raiden [163] and Plasma [164].”

• cites [162] sourceNot checked yet

  Not checked in the free run.

• cites [163] sourceNot checked yet

  Not checked in the free run.

• cites [164]Not checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S4 (based). May combine two claims.

Blockchain has been successfully used for cryptocurrencies and can enhance Industry 4.0 technologies by adding security, trust, immutability, disintermediation, decentralization and a higher degree of automation through smart contracts.

“blockchain, which has been successfully used for cryptocurrencies and which can enhance Industry 4.0 technologies by adding security, trust, immutability, disintermediation, decentralization and a higher degree of automation through smart contracts.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The IEEE Standards Association is driving two relevant initiatives related to blockchain: one for optimizing clinical trials and enhancing patient safety, and another for advancing blockchain adoption within the pharmaceutical industry.

“two relevant initiatives are being driven by the IEEE Standards Association [167] in relation to blockchain: one related to build consensus on optimizing clinical trials and enhancing patient safety, and another one for driving collaboration on advancing blockchain adoption within the pharmaceutical industry.”

• cites [167] sourceNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

Data privacy, identity certification and data integrity are still issues that need to be addressed properly, especially for resource-constraint devices.

“data privacy, identity certification and data integrity are still issues that need to be addressed properly, especially for resource-constraint devices.”

May combine two claims.

Blockchain throughput and latency usually increase latency and reduce throughput respect to traditional database systems, so it may be difficult to provide real-time responses to events.

“both factors usually increase latency and reduce remarkably the throughout respect to, for instance, traditional database systems, so it may be difficult to provide real-time responses to events.”

May combine two claims.

The use of mining, inefficient P2P protocols and computationally complex cryptographic algorithms have an impact on energy consumption in every scenario, critical when battery-operated devices are used.

“the use of mining, inefficient P2P protocols and computationally complex cryptographic algorithms have an impact on the energy consumption in every scenario, although such factors are critical when battery-operated devices are used.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

The foreseen high amount of data traffic generated by P2P communications requires communications infrastructure and interfaces able to support the estimated load.

“the foreseen high amount of data traffic generated by P2P communications require communications infrastructure and interfaces able to support the estimated load.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The proliferation of blockchains may require some companies to support several of them simultaneously.

“The proliferation of blockchains may require some companies to support several of them simultaneously.”

Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing). May combine two claims.

Industries that need to keep data secure for the medium and long-term should be aware of the threat of post-quantum computing and look for energy-efficient quantum-safe algorithms.

“the industries that need to keep data secure for the medium and long-term should be aware of the threat of post-quantum computing [157] and look for energy-efficient quantumsafe algorithms.”

• cites [157]Not checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

The use of blockchain technologies requires deploying specific hardware infrastructure, like additional storage or mining hardware.

“The use of blockchain technologies requires to deploy specific hardware infrastructure, like additional storage or mining hardware.”