This article outlines the benefits and risks of the distributed ledger technology(DLT)for the clearing and settlement of exchange-traded and OTC securities,followed by a description of the technology’s potential role...This article outlines the benefits and risks of the distributed ledger technology(DLT)for the clearing and settlement of exchange-traded and OTC securities,followed by a description of the technology’s potential role for central counterparties and central securities depositories.Although the industry and scholars are attempting to solve the technological and operational issues that DLT systems still face,outstanding legal risks are such that the financial industry is asking for more regulatory guidance and intervention.This article wants to contribute to the public policy debate by presenting potential regulatory barriers that may have to be removed for DLT to be fully adopted.In addition,it identifies areas requiring an update of the legal framework in order to address certain prudential and conduct risks that this technology could introduce.展开更多
As one of the most concerned digital technologies in recent years,blockchain and distributed ledger technology are an important driving force for a new round of technological development.It is currently in the process...As one of the most concerned digital technologies in recent years,blockchain and distributed ledger technology are an important driving force for a new round of technological development.It is currently in the process of accelerating its evolution and maturity,and has gradually integrated with other digital technologies.It has been applied in many industries,providing decentralized solutions for various industries,realizing innovative storage models,and building a new trust system.As blockchain technology is officially incorporated into China’s new information infrastructure category,the application fields of blockchain have expanded rapidly,gradually extending from the financial field and government affairs to other fields in the real economy.At the same time,with the continuous development of the globalized economy,blockchain technology will also have a profound impact on international technological and economic development.Therefore,for the healthy and orderly development and real implementation of the blockchain industry,standardize the application of blockchain,effectively break through the cognitive and technical barriers between different countries,industries and systems on a global scale,prevent application risks,the development of the global blockchain industry needs standardization basis,which is particularly important and urgent.A sound standard system is an important key to the successful development of technology,and formulating the right standard at the right time for technology development helps ensure the ease of use and interoperability of the technology.From the perspective of international standardization,this article first introduces the general situation of ISO,ITU-T,IEEE,W3C and other international standardization organizations,and sorts out the status quo of the blockchain standardization working groups of mainstream international standardization organizations.All blockchain-related standards under development have been analyzed for the characteristics of international blockchain technology standards and industry application standards.Through data analysis,the overlaps,differences and conflicts in the field of international blockchain standard formulation are sorted out,and suggestions for blockchain standardization work in the application and development of blockchain technology standardization by international organizations and industries are put forward.The plans and layouts of future international standards are summarized to help the development of the international standardization of blockchain.展开更多
A zero-knowledge proof or protocol is a cryptographic technique for verifying private data without revealing it in its clear form.In this paper,we evaluate the potential for zero-knowledge distributed ledger technolog...A zero-knowledge proof or protocol is a cryptographic technique for verifying private data without revealing it in its clear form.In this paper,we evaluate the potential for zero-knowledge distributed ledger technology to alleviate asymmetry of information in the asset-backed securitization market.To frame this inquiry,we conducted market data analyses,a review of prior literature,stakeholder interviews with investors,originators and security issuers and collaboration with blockchain engineers and researchers.We introduce a new system which could enable all market participants in the securitization lifecycle(e.g.investors,rating agencies,regulators and security issuers)to interact on a unique decentralized platform while maintaining the privacy of loan-level data,therefore providing the industry with timely analytics and performance data.Our platform is powered by zkLedger(Narula et al.2018),a zero-knowledge protocol developed by the MIT Media Lab and the first system that enables participants of a distributed ledger to run publicly verifiable analytics on masked data.展开更多
Election allows the voter of a country to select the most suitable group of candidates to run the government.Election in Pakistan is simply paper-based method but some certain political and socio-economic issues turn ...Election allows the voter of a country to select the most suitable group of candidates to run the government.Election in Pakistan is simply paper-based method but some certain political and socio-economic issues turn that simple process in complicated and disputes once.Solutions of such problems are consisting of many methods including the e-voting system.The e-voting system facilitates the voters to cast their votes by electronic means with very easy and convenient way.This also allows maintaining the security and secrecy of the voter along with election process.Electronic voting reduces the human-involvement throughout the process from start to the end.Such system is not established yet in Pakistan.Hence,every election is disputed always.In this paper we proposed the framework of an e-voting system and simulation with the use of blockchain ledger technology.The proposed framework owns the capacity to deal with ballots in Pakistan.The novelty of the framework is that the e-voting system is linked to National Database and Registration Authority(NADRA)database which assures voter’s validation.The fundamental requirements were kept in consideration during the performance evaluation of the system.The results are processed and depicted specially with reference to the number of voters and voting stations,real time of vote casting,network bandwidth and controlling principles.The results support the decision makers and guide them in the foundation and customization of an e-voting system in Pakistan.展开更多
Privacy-preservation and effective auditing are two desirable but challenging requirements on distributed ledgers. To meet the requirements, this paper presents an auditing scheme, called as AudiTEE, which can audit a...Privacy-preservation and effective auditing are two desirable but challenging requirements on distributed ledgers. To meet the requirements, this paper presents an auditing scheme, called as AudiTEE, which can audit a distributed ledger in a generic, efficient, and privacy-preserving manner. AudiTEE leverages Trusted Execution Environment (TEE) to generate confidential but auditable transactions and realize arbitrary, efficient and confidential audit on them. Unfortunately, TEE suffers from some inherent barriers and is itself not a complete solution for fast audit. To tackle these challenges, AudiTEE takes advantage of KAMT (K-anonymity Authentication Based on Merkle Tree) protocol for efficient management on account and user-defined anonymous transactions. Further, to achieve a complete and fast audit with <i>unlinkability</i>, TEE doesn’t process through all but only a comparatively small part of transactions according to a special <i>ktag</i> attached on each transaction to ensure that a user cannot hide transactions from auditor even when auditor is blind with who is involved in each transaction on the ledger. Apart from the above, AudiTEE allows flexible control on user behaviors. We implement a concrete instance of AudiTEE under a bank setting and demonstrate the scalability with all its core functionalities.展开更多
Due to the advantages of high volume of transactions and low resource consumption,Directed Acyclic Graph(DAG)-based Distributed Ledger Technology(DLT)has been considered a possible next-generation alternative to block...Due to the advantages of high volume of transactions and low resource consumption,Directed Acyclic Graph(DAG)-based Distributed Ledger Technology(DLT)has been considered a possible next-generation alternative to blockchain.However,the security of the DAG-based system has yet to be comprehensively understood.Aiming at verifying and evaluating the security of DAG-based DLT,we develop a Multi-Agent based IOTA Simulation platform called MAIOTASim.In MAIOTASim,we model honest and malicious nodes and simulate the configurable network environment,including network topology and delay.The double-spending attack is a particular security issue related to DLT.We perform the security verification of the consensus algorithms under multiple double-spending attack strategies.Our simulations show that the consensus algorithms can resist the parasite chain attack and partially resist the splitting attack,but they are ineffective under the large weight attack.We take the cumulative weight difference of transactions as the evaluation criterion and analyze the effect of different consensus algorithms with parameters under each attack strategy.Besides,MAIOTASim enables users to perform largescale simulations with multiple nodes and tens of thousands of transactions more efficiently than state-of-the-art ones.展开更多
Since the publication of Satoshi Nakamoto's white paper on Bitcoin in 2008,blockchain has(slowly)become one of the most frequently discussed methods for securing data storage and transfer through decentralized,tru...Since the publication of Satoshi Nakamoto's white paper on Bitcoin in 2008,blockchain has(slowly)become one of the most frequently discussed methods for securing data storage and transfer through decentralized,trustless,peer-to-peer systems.This research identifies peer-reviewed literature that seeks to utilize blockchain for cyber security purposes and presents a systematic analysis of the most frequently adopted blockchain security applications.Our findings show that the Internet of Things(IoT)lends itself well to novel blockchain applications,as do networks and machine visualization,public-key cryptography,web applications,certification schemes and the secure storage of Personally Identifiable Information(PII).This timely systematic review also sheds light on future directions of research,education and practices in the blockchain and cyber security space,such as security of blockchain in IoT,security of blockchain for AI data,and sidechain security.展开更多
Supply chain traceability is one of the most promising use cases to benefit from characteristics of blockchain,such as decentralization,immutability and transparency,not required to build prior trust relationships amo...Supply chain traceability is one of the most promising use cases to benefit from characteristics of blockchain,such as decentralization,immutability and transparency,not required to build prior trust relationships among entities.A plethora of supply chain traceability solutions based on blockchain has been proposed recently.However,current systems are limited to tracing simple goods that have not been part of the manufacturing process.We recommend a method that allows for the traceability of manufactured goods,including their components.Products are represented using non-fungible digital tokens that are created on a blockchain for each batch of manufactured products.To create a link between a product and the components that are needed to produce it,we propose“token recipes”that define the amount of tokenized goods required for minting a new token.As input tokens are automatically and transparently consumed when creating a product token,the physical process of producing a new item out of existing components is projected onto the ledger.This ultimately leads to the complete traceability of goods,including the origin of inputs.Evaluating the performance of the system,we show that a prototypical implementation for the Ethereum Virtual Machine(EVM)scales linearly with the amount of the input and goods tracked.展开更多
With the development of blockchain technology,a variety of mutually independent blockchains such as Bitcoin and Ethereum,as well as private and consortium chains,coexist in large numbers.As a linker of the blockchain ...With the development of blockchain technology,a variety of mutually independent blockchains such as Bitcoin and Ethereum,as well as private and consortium chains,coexist in large numbers.As a linker of the blockchain network,blockchain interoperability will link more blockchain ecosystems,realize the interconnection of the blockchain and enhance the scalability of the blockchain.This paper summarizes typical blockchain interoperability projects.Firstly,it proposes a blockchain interoperability definition and an architecture model.Secondly,it analyzes technical characteristics of blockchain interoperability,and typical blockchain interoperability cases are compared.Finally,the trend of future development of blockchain interoperability technology is summarized and discussed.展开更多
This study discusses the European Union’s proposal for a Regulation on Markets in Crypto-Assets,now subject to formal approval by the European Parliament.The objective is to explore whether it will positively impact ...This study discusses the European Union’s proposal for a Regulation on Markets in Crypto-Assets,now subject to formal approval by the European Parliament.The objective is to explore whether it will positively impact the adoption of crypto-assets in the financial sector.The use of crypto-assets is growing.However,some stakeholders in the financial service sector remain skeptical and hesitant to adopt assets that are yet to be defined and have an unclear legal status.This regulatory uncertainty has been identified as the primary reason for the reluctant adoption.The proposed regulation(part of the EU’s Digital Finance Strategy)aims to provide this legal certainty for currently unregulated crypto-assets.This study investigates whether or not the proposed regulation can be expected to have the intended effect by reviewing the proposed regulation itself,the opinions and reactions of the various stakeholders,and secondary literature.Findings reveal that such regulation will most likely not accelerate the adoption of crypto-assets in the EU financial services sector,at least not sufficiently or as intended.Some suggestions are made to improve the proposal.展开更多
As digital data circulation increases,information pollution and manipulation in journalism have become more prevalent.In this study,a new digital journalism model is designed to contribute to the solution of the main ...As digital data circulation increases,information pollution and manipulation in journalism have become more prevalent.In this study,a new digital journalism model is designed to contribute to the solution of the main current problems,such as information pollution,manipulation,and account-ability in digital journalism.The model uses blockchain technology due to its transparency,immutability,and traceability.However,it is tough to provide the mechanisms necessary for journalism,such as updating one piece of information,instantly updating all other information affected by the updated information,establishing logical relationships between news,making quick comparisons,sorting and indexing news,and keeping the changing informa-tion about the news in the system,with the blockchain data structure.For this reason,in our study,we have developed a new data structure that provides both the immutability,transparency and traceability properties of the blockchain and can support the communication mechanisms necessary for journalism.The functionality of our proposed data structure is demonstrated in terms of communication mechanisms such as mutability,context,consistency,and reliability through example scenarios.Additionally,our data structure is compared with the data structure of blockchain technology in terms of time,space,and maintenance costs.Accordingly,while the model size increases linearly in blockchain,the model’s size remains approximately constant since the structure we developed is data-independent.In this way,maintenance costs are reduced.Since our model also has an indexing mechanism,it reduces the linear time search complexity to logarithmic time.As a result,the data structure we developed is found to have higher performance than blockchain in the journalism concept.In future studies,it is planned to test all aspects of the model with a pilot application,eliminate its shortcomings,and develop a holistic approach to the root causes of the problems in the journalism focus.展开更多
Pandemics have always been a nightmare for humanity,especially in developing countries.Forced lockdowns are considered one of the effective ways to deal with spreading such pandemics.Still,developing countries cannot ...Pandemics have always been a nightmare for humanity,especially in developing countries.Forced lockdowns are considered one of the effective ways to deal with spreading such pandemics.Still,developing countries cannot afford such solutions because these may severely damage the country’s econ-omy.Therefore,this study presents the proactive technological mechanisms for business organizations to run their standard business processes during pandemic-like situations smoothly.The novelty of this study is to provide a state-of-the-art solution to prevent pandemics using industrial internet of things(IIoT)and blockchain-enabled technologies.Compared to existing studies,the immutable and tamper-proof contact tracing and quarantine management solution is proposed.The use of advanced technologies and information security is a critical area for practitioners in the internet of things(IoT)and corresponding solutions.Therefore,this study also emphasizes information security,end-to-end solution,and experimental results.Firstly,a wearable wristband is proposed,incorporating 4G-enabled ultra-wideband(UWB)technology for smart contact tracing mechanisms in industries to comply with standard operating procedures outlined by the world health organization(WHO).Secondly,distributed ledger technology(DLT)omits the centralized dependency for transmitting contact tracing data.Thirdly,a privacy-preserving tracing mechanism is discussed using a public/private key cryptography-based authentication mechanism.Lastly,based on geofencing techniques,blockchain-enabled machine-to-machine(M2M)technology is proposed for quarantine management.The step-by-step methodology and test results are proposed to ensure contact tracing and quarantine management.Unlike existing research studies,the security aspect is also considered in the realm of blockchain.The practical implementation of the proposed solution also obtains the results.The results indicate the successful implementation of blockchain-enabled contact tracing and isolation management using IoT and geo-fencing techniques,which could help battle pandemic situations.Researchers can also consider the 5G-enabled narrowband internet of things(NB-IoT)technologies to implement contact tracing solutions.展开更多
<span style="font-family:Verdana;">The 21<sup>st</sup> Century is all about technology. People are open to accepting new technologies as the need for modernization is increasing every singl...<span style="font-family:Verdana;">The 21<sup>st</sup> Century is all about technology. People are open to accepting new technologies as the need for modernization is increasing every single day. Blockchain is one of those new and revolutionary technologies that will have a significant impact on the market and industry. In layman’s terms, Blockchain is a data structure that stores transactional records while also ensuring security, transparency, and decentralization. There is a digital signature on every transaction on a blockchain, which proves the authenticity of the blockchain. In a Blockchain, data is stored which is tamper-proof and cannot be changed as it uses encryption and digital signatures. To change a record on a blockchain, one needs to change several records, and one needs to change the distributed ledger. That’s why it’s quite impossible to change the data which has already been entered into a Blockchain. The Blockchain is a technology that will allow transactions simply, safely, effectively, and also safely. This is a very promising technology. It’s already in a lot of places. It can also solve any problem in the banking sector. This technology became famous after introducing the first cryptocurrency, which is known as bitcoin. Right now, there is a huge problem with banking, and the Blockchain can solve these problems. This paper will demonstrate transacting over a secure, blockchain-based network and therefore eliminate the need for intermediary entities. This paper is a review-based paper that provides the application and opportunities of the Blockchain in the banking system. The purpose of this paper is to provide a review of the application and opportunities of the Blockchain for a secure banking system. In this review investigation and analysis of this paper at the beginning, related work from other authors in the same fields has been discussed. Then the working method of the Blockchain technology has been introduced with analysis. The use of blockchain technology for secure banking has been discussed. The main achievement of this paper is to demonstrate how the Blockchain works and how it can be useful in the secure banking industry.</span>展开更多
In recent years,blockchain technologies have expanded from the finance field to other areas that rely on trustbased solutions.The healthcare industry represents one such area,as digital transformation disrupts relatio...In recent years,blockchain technologies have expanded from the finance field to other areas that rely on trustbased solutions.The healthcare industry represents one such area,as digital transformation disrupts relationships between patients,healthcare professionals,and healthcare institutes.Patients and healthcare institutes lack a proficient tool to verify the credentials of medical professionals in a digital environment.Furthermore,healthcare professionals lack a tool where they are in control over their credentials.The first contribution of this paper is a proposal of a solution that leverages the private permissioned Hyperledger Fabric blockchain and smart contracts to provide a source of transparent trust for relationships within the healthcare industry.Second,we pave the ground for GDPR compliance by storing only the hash values on the blockchain.Third,we solve the problem of patient authentication by utilizing cryptographic techniques.Finally,we prove the usability of the proposed solution by implementing a user interface and creating a live deployment.展开更多
Blockchain is gaining massive attention and has the potential to impact different types of record-keeping processes.It is one of the most innovative technologies potential enough to impact every industry from financia...Blockchain is gaining massive attention and has the potential to impact different types of record-keeping processes.It is one of the most innovative technologies potential enough to impact every industry from financial to educational institutes.Recently,consensus mechanisms have enabled distributed ledger technologies(DLTs)to find their applications and values in various sectors.A consensus algorithm is an essential element of blockchain networks.Consensus mechanisms function to ensure the transaction's validity,reliability,and authenticity in a peer-to-peer network.The consensus algorithm assures the authenticity of transactions in a trustless and distributed manner.Choosing the right consensus algorithm plays a crucial role in the performance of a blockchain application.In this paper,a detailed survey of different types of blockchain consensus algorithms that are popular and commonly used today is presented.展开更多
Easy access to data is one of the main avenues to accelerate scientific research.As a key element of scientific innovations,data sharing allows the reproduction of results and helps prevent data fabrication,falsificat...Easy access to data is one of the main avenues to accelerate scientific research.As a key element of scientific innovations,data sharing allows the reproduction of results and helps prevent data fabrication,falsification,and misuse.Although the research benefits from data reuse are widely acknowledged,the data collections existing today are still kept in silos.Indeed,monitoring what happens to data once they have been handed to a third party is currently not feasible within the current data sharing practices.We propose a blockchain-based system to trace data collections and potentially create a more trustworthy data sharing process.In this paper,we present the LUCE(License accoUntability and CompliancE)architecture as a decentralized blockchain-based platform supporting data sharing and reuse.LUCE is designed to provide full transparency on what happens to the data after they are shared with third parties.The contributions of this work consist of i)the design of a decentralized data sharing solution with accountability and compliance by design and ii)the inclusion of a dynamic consent model for personalized data sharing preferences and for enabling legal compliance mechanisms.We test the scalability of the platform in a real-time environment where a growing number of users access and reuse different datasets.Compared to existing data sharing solutions,LUCE provides transparency over data sharing practices,enables data reuse,and supports regulatory requirements.The experimentation shows that the platform can be scaled for a large number of users.展开更多
Identity management has been ripe for disruption over the past few years due to recurring incidents of data breaches that have led to personal information leaks and identity theft.The rise of blockchain technology has...Identity management has been ripe for disruption over the past few years due to recurring incidents of data breaches that have led to personal information leaks and identity theft.The rise of blockchain technology has paved the way for the development of self-sovereign identity(SSI)—a new class of user-controlled resilient identity management systems that are enabled by distributed ledger technology.This paper examines how SSI management can be used in a public transportation sector that spans different operators in multiple countries.Specifically,the paper explores how a blockchain-based decentralized identity management system can draw on the SSI framework to provide high-level security and transparency for all involved parties in public transportation ecosystems.Accordingly,building on analyses of the existing public transportation ticketing solutions,we elicited requirements of a comparable system based on the SSI principles.Next,we developed a low-fidelity prototype to showcase how passengers can utilize standardized travel credentials that are valid across different transportation networks in Europe.The proposed system eliminates the need for multiple travel cards(i.e.,one for each transportation provider)and empowers individuals to have better control over the use of their identities while they utilize interoperable ticketing systems across Europe.Overall,building on the public transportation case,we offer a proof-of-concept that shows how individuals can better manage their identity credentials via the SSI framework.展开更多
At present, there is an urgent need for blockchain interoperability technology to realize interconnection between various blockchains, data communication and value transfer between blockchains, so as to break the ‘va...At present, there is an urgent need for blockchain interoperability technology to realize interconnection between various blockchains, data communication and value transfer between blockchains, so as to break the ‘value silo’ phenomenon of each blockchain. Firstly, it lists what people understand about the concept of interoperability. Secondly, it gives the key technical issues of cross-chain, including cross-chain mechanism, interoperability, eventual consistency, and universality. Then, the implementation of each cross-chain key technology is analyzed, including Hash-locking, two-way peg, notary schemes, relay chain scheme, cross-chain protocol, and global identity system. Immediately after that, five typical cross-chain systems are introduced and comparative analysis is made. In addition, two examples of cross-chain programmability and their analysis are given. Finally, the current state of cross-chain technology is summarized from two aspects: key technology implementation and cross-chain application enforcement. The cross-chain technology as a whole has formed a centralized fixed mechanism, as well as a trend of modular design, and some of the solutions to mature applications were established in the relevant standards organizations, and the cross-chain technology architecture tends to be unified, which is expected to accelerate the evolution of the open cross-chain network that supports the real needs of the interconnection of all chains.展开更多
Threshold proxy re-encryption(PRE) authorizes the data access right of data subject to multiple proxies, who authorize the right again to delegatee to accomplish the end-to-end data encryption process from storage to ...Threshold proxy re-encryption(PRE) authorizes the data access right of data subject to multiple proxies, who authorize the right again to delegatee to accomplish the end-to-end data encryption process from storage to authorization. Based on threshold PRE algorithm, in order to build a complete trusted data storage and authorization system, the four protocols, which are data access protocol, authorization proxy protocol, authorization proxy cancellation protocol and data reading authorization protocol, are defined completely. On that basis, an efficient data searching method is constructed by specifying the data delegatee. At last, to ensure the right to know of data, the audit log is processed with trusted data right confirmation based on distributed ledger technology. Meanwhile, a parallel data right confirmation processing method is defined based on hierarchical derivation algorithm of public and private key. In the end, the performance evaluation analysis of the protocol are given. Trusted data access and authorization protocol is convenient to build a complete data processing system on the premise of protecting data privacy based on public cloud storage system or distributed storage system.展开更多
文摘This article outlines the benefits and risks of the distributed ledger technology(DLT)for the clearing and settlement of exchange-traded and OTC securities,followed by a description of the technology’s potential role for central counterparties and central securities depositories.Although the industry and scholars are attempting to solve the technological and operational issues that DLT systems still face,outstanding legal risks are such that the financial industry is asking for more regulatory guidance and intervention.This article wants to contribute to the public policy debate by presenting potential regulatory barriers that may have to be removed for DLT to be fully adopted.In addition,it identifies areas requiring an update of the legal framework in order to address certain prudential and conduct risks that this technology could introduce.
基金supported by the Key R&D Program of Zhejiang Province(2021C01105)the Key R&D Program of Guangdong Province(2020B0101090003)+1 种基金the National Key R&D Program of China(2021YFB2701100)These supports are gratefully acknowledged.
文摘As one of the most concerned digital technologies in recent years,blockchain and distributed ledger technology are an important driving force for a new round of technological development.It is currently in the process of accelerating its evolution and maturity,and has gradually integrated with other digital technologies.It has been applied in many industries,providing decentralized solutions for various industries,realizing innovative storage models,and building a new trust system.As blockchain technology is officially incorporated into China’s new information infrastructure category,the application fields of blockchain have expanded rapidly,gradually extending from the financial field and government affairs to other fields in the real economy.At the same time,with the continuous development of the globalized economy,blockchain technology will also have a profound impact on international technological and economic development.Therefore,for the healthy and orderly development and real implementation of the blockchain industry,standardize the application of blockchain,effectively break through the cognitive and technical barriers between different countries,industries and systems on a global scale,prevent application risks,the development of the global blockchain industry needs standardization basis,which is particularly important and urgent.A sound standard system is an important key to the successful development of technology,and formulating the right standard at the right time for technology development helps ensure the ease of use and interoperability of the technology.From the perspective of international standardization,this article first introduces the general situation of ISO,ITU-T,IEEE,W3C and other international standardization organizations,and sorts out the status quo of the blockchain standardization working groups of mainstream international standardization organizations.All blockchain-related standards under development have been analyzed for the characteristics of international blockchain technology standards and industry application standards.Through data analysis,the overlaps,differences and conflicts in the field of international blockchain standard formulation are sorted out,and suggestions for blockchain standardization work in the application and development of blockchain technology standardization by international organizations and industries are put forward.The plans and layouts of future international standards are summarized to help the development of the international standardization of blockchain.
基金We received funding solely from our institution to perform this research.
文摘A zero-knowledge proof or protocol is a cryptographic technique for verifying private data without revealing it in its clear form.In this paper,we evaluate the potential for zero-knowledge distributed ledger technology to alleviate asymmetry of information in the asset-backed securitization market.To frame this inquiry,we conducted market data analyses,a review of prior literature,stakeholder interviews with investors,originators and security issuers and collaboration with blockchain engineers and researchers.We introduce a new system which could enable all market participants in the securitization lifecycle(e.g.investors,rating agencies,regulators and security issuers)to interact on a unique decentralized platform while maintaining the privacy of loan-level data,therefore providing the industry with timely analytics and performance data.Our platform is powered by zkLedger(Narula et al.2018),a zero-knowledge protocol developed by the MIT Media Lab and the first system that enables participants of a distributed ledger to run publicly verifiable analytics on masked data.
文摘Election allows the voter of a country to select the most suitable group of candidates to run the government.Election in Pakistan is simply paper-based method but some certain political and socio-economic issues turn that simple process in complicated and disputes once.Solutions of such problems are consisting of many methods including the e-voting system.The e-voting system facilitates the voters to cast their votes by electronic means with very easy and convenient way.This also allows maintaining the security and secrecy of the voter along with election process.Electronic voting reduces the human-involvement throughout the process from start to the end.Such system is not established yet in Pakistan.Hence,every election is disputed always.In this paper we proposed the framework of an e-voting system and simulation with the use of blockchain ledger technology.The proposed framework owns the capacity to deal with ballots in Pakistan.The novelty of the framework is that the e-voting system is linked to National Database and Registration Authority(NADRA)database which assures voter’s validation.The fundamental requirements were kept in consideration during the performance evaluation of the system.The results are processed and depicted specially with reference to the number of voters and voting stations,real time of vote casting,network bandwidth and controlling principles.The results support the decision makers and guide them in the foundation and customization of an e-voting system in Pakistan.
文摘Privacy-preservation and effective auditing are two desirable but challenging requirements on distributed ledgers. To meet the requirements, this paper presents an auditing scheme, called as AudiTEE, which can audit a distributed ledger in a generic, efficient, and privacy-preserving manner. AudiTEE leverages Trusted Execution Environment (TEE) to generate confidential but auditable transactions and realize arbitrary, efficient and confidential audit on them. Unfortunately, TEE suffers from some inherent barriers and is itself not a complete solution for fast audit. To tackle these challenges, AudiTEE takes advantage of KAMT (K-anonymity Authentication Based on Merkle Tree) protocol for efficient management on account and user-defined anonymous transactions. Further, to achieve a complete and fast audit with <i>unlinkability</i>, TEE doesn’t process through all but only a comparatively small part of transactions according to a special <i>ktag</i> attached on each transaction to ensure that a user cannot hide transactions from auditor even when auditor is blind with who is involved in each transaction on the ledger. Apart from the above, AudiTEE allows flexible control on user behaviors. We implement a concrete instance of AudiTEE under a bank setting and demonstrate the scalability with all its core functionalities.
基金supported by the National Natural Science Foundation of China(Grant No.62071151)。
文摘Due to the advantages of high volume of transactions and low resource consumption,Directed Acyclic Graph(DAG)-based Distributed Ledger Technology(DLT)has been considered a possible next-generation alternative to blockchain.However,the security of the DAG-based system has yet to be comprehensively understood.Aiming at verifying and evaluating the security of DAG-based DLT,we develop a Multi-Agent based IOTA Simulation platform called MAIOTASim.In MAIOTASim,we model honest and malicious nodes and simulate the configurable network environment,including network topology and delay.The double-spending attack is a particular security issue related to DLT.We perform the security verification of the consensus algorithms under multiple double-spending attack strategies.Our simulations show that the consensus algorithms can resist the parasite chain attack and partially resist the splitting attack,but they are ineffective under the large weight attack.We take the cumulative weight difference of transactions as the evaluation criterion and analyze the effect of different consensus algorithms with parameters under each attack strategy.Besides,MAIOTASim enables users to perform largescale simulations with multiple nodes and tens of thousands of transactions more efficiently than state-of-the-art ones.
文摘Since the publication of Satoshi Nakamoto's white paper on Bitcoin in 2008,blockchain has(slowly)become one of the most frequently discussed methods for securing data storage and transfer through decentralized,trustless,peer-to-peer systems.This research identifies peer-reviewed literature that seeks to utilize blockchain for cyber security purposes and presents a systematic analysis of the most frequently adopted blockchain security applications.Our findings show that the Internet of Things(IoT)lends itself well to novel blockchain applications,as do networks and machine visualization,public-key cryptography,web applications,certification schemes and the secure storage of Personally Identifiable Information(PII).This timely systematic review also sheds light on future directions of research,education and practices in the blockchain and cyber security space,such as security of blockchain in IoT,security of blockchain for AI data,and sidechain security.
基金The research conducted has been funded by Deutsche Telekom,Bonn,Germany and EIT Digital,Brussels,Belgium as part of the eBIZ project with grant number 17148-18.
文摘Supply chain traceability is one of the most promising use cases to benefit from characteristics of blockchain,such as decentralization,immutability and transparency,not required to build prior trust relationships among entities.A plethora of supply chain traceability solutions based on blockchain has been proposed recently.However,current systems are limited to tracing simple goods that have not been part of the manufacturing process.We recommend a method that allows for the traceability of manufactured goods,including their components.Products are represented using non-fungible digital tokens that are created on a blockchain for each batch of manufactured products.To create a link between a product and the components that are needed to produce it,we propose“token recipes”that define the amount of tokenized goods required for minting a new token.As input tokens are automatically and transparently consumed when creating a product token,the physical process of producing a new item out of existing components is projected onto the ledger.This ultimately leads to the complete traceability of goods,including the origin of inputs.Evaluating the performance of the system,we show that a prototypical implementation for the Ethereum Virtual Machine(EVM)scales linearly with the amount of the input and goods tracked.
基金supported in part by the 2020 Industrial Internet Innovation and Development Project:Network Identifier Construction Project。
文摘With the development of blockchain technology,a variety of mutually independent blockchains such as Bitcoin and Ethereum,as well as private and consortium chains,coexist in large numbers.As a linker of the blockchain network,blockchain interoperability will link more blockchain ecosystems,realize the interconnection of the blockchain and enhance the scalability of the blockchain.This paper summarizes typical blockchain interoperability projects.Firstly,it proposes a blockchain interoperability definition and an architecture model.Secondly,it analyzes technical characteristics of blockchain interoperability,and typical blockchain interoperability cases are compared.Finally,the trend of future development of blockchain interoperability technology is summarized and discussed.
文摘This study discusses the European Union’s proposal for a Regulation on Markets in Crypto-Assets,now subject to formal approval by the European Parliament.The objective is to explore whether it will positively impact the adoption of crypto-assets in the financial sector.The use of crypto-assets is growing.However,some stakeholders in the financial service sector remain skeptical and hesitant to adopt assets that are yet to be defined and have an unclear legal status.This regulatory uncertainty has been identified as the primary reason for the reluctant adoption.The proposed regulation(part of the EU’s Digital Finance Strategy)aims to provide this legal certainty for currently unregulated crypto-assets.This study investigates whether or not the proposed regulation can be expected to have the intended effect by reviewing the proposed regulation itself,the opinions and reactions of the various stakeholders,and secondary literature.Findings reveal that such regulation will most likely not accelerate the adoption of crypto-assets in the EU financial services sector,at least not sufficiently or as intended.Some suggestions are made to improve the proposal.
文摘As digital data circulation increases,information pollution and manipulation in journalism have become more prevalent.In this study,a new digital journalism model is designed to contribute to the solution of the main current problems,such as information pollution,manipulation,and account-ability in digital journalism.The model uses blockchain technology due to its transparency,immutability,and traceability.However,it is tough to provide the mechanisms necessary for journalism,such as updating one piece of information,instantly updating all other information affected by the updated information,establishing logical relationships between news,making quick comparisons,sorting and indexing news,and keeping the changing informa-tion about the news in the system,with the blockchain data structure.For this reason,in our study,we have developed a new data structure that provides both the immutability,transparency and traceability properties of the blockchain and can support the communication mechanisms necessary for journalism.The functionality of our proposed data structure is demonstrated in terms of communication mechanisms such as mutability,context,consistency,and reliability through example scenarios.Additionally,our data structure is compared with the data structure of blockchain technology in terms of time,space,and maintenance costs.Accordingly,while the model size increases linearly in blockchain,the model’s size remains approximately constant since the structure we developed is data-independent.In this way,maintenance costs are reduced.Since our model also has an indexing mechanism,it reduces the linear time search complexity to logarithmic time.As a result,the data structure we developed is found to have higher performance than blockchain in the journalism concept.In future studies,it is planned to test all aspects of the model with a pilot application,eliminate its shortcomings,and develop a holistic approach to the root causes of the problems in the journalism focus.
文摘Pandemics have always been a nightmare for humanity,especially in developing countries.Forced lockdowns are considered one of the effective ways to deal with spreading such pandemics.Still,developing countries cannot afford such solutions because these may severely damage the country’s econ-omy.Therefore,this study presents the proactive technological mechanisms for business organizations to run their standard business processes during pandemic-like situations smoothly.The novelty of this study is to provide a state-of-the-art solution to prevent pandemics using industrial internet of things(IIoT)and blockchain-enabled technologies.Compared to existing studies,the immutable and tamper-proof contact tracing and quarantine management solution is proposed.The use of advanced technologies and information security is a critical area for practitioners in the internet of things(IoT)and corresponding solutions.Therefore,this study also emphasizes information security,end-to-end solution,and experimental results.Firstly,a wearable wristband is proposed,incorporating 4G-enabled ultra-wideband(UWB)technology for smart contact tracing mechanisms in industries to comply with standard operating procedures outlined by the world health organization(WHO).Secondly,distributed ledger technology(DLT)omits the centralized dependency for transmitting contact tracing data.Thirdly,a privacy-preserving tracing mechanism is discussed using a public/private key cryptography-based authentication mechanism.Lastly,based on geofencing techniques,blockchain-enabled machine-to-machine(M2M)technology is proposed for quarantine management.The step-by-step methodology and test results are proposed to ensure contact tracing and quarantine management.Unlike existing research studies,the security aspect is also considered in the realm of blockchain.The practical implementation of the proposed solution also obtains the results.The results indicate the successful implementation of blockchain-enabled contact tracing and isolation management using IoT and geo-fencing techniques,which could help battle pandemic situations.Researchers can also consider the 5G-enabled narrowband internet of things(NB-IoT)technologies to implement contact tracing solutions.
文摘<span style="font-family:Verdana;">The 21<sup>st</sup> Century is all about technology. People are open to accepting new technologies as the need for modernization is increasing every single day. Blockchain is one of those new and revolutionary technologies that will have a significant impact on the market and industry. In layman’s terms, Blockchain is a data structure that stores transactional records while also ensuring security, transparency, and decentralization. There is a digital signature on every transaction on a blockchain, which proves the authenticity of the blockchain. In a Blockchain, data is stored which is tamper-proof and cannot be changed as it uses encryption and digital signatures. To change a record on a blockchain, one needs to change several records, and one needs to change the distributed ledger. That’s why it’s quite impossible to change the data which has already been entered into a Blockchain. The Blockchain is a technology that will allow transactions simply, safely, effectively, and also safely. This is a very promising technology. It’s already in a lot of places. It can also solve any problem in the banking sector. This technology became famous after introducing the first cryptocurrency, which is known as bitcoin. Right now, there is a huge problem with banking, and the Blockchain can solve these problems. This paper will demonstrate transacting over a secure, blockchain-based network and therefore eliminate the need for intermediary entities. This paper is a review-based paper that provides the application and opportunities of the Blockchain in the banking system. The purpose of this paper is to provide a review of the application and opportunities of the Blockchain for a secure banking system. In this review investigation and analysis of this paper at the beginning, related work from other authors in the same fields has been discussed. Then the working method of the Blockchain technology has been introduced with analysis. The use of blockchain technology for secure banking has been discussed. The main achievement of this paper is to demonstrate how the Blockchain works and how it can be useful in the secure banking industry.</span>
文摘In recent years,blockchain technologies have expanded from the finance field to other areas that rely on trustbased solutions.The healthcare industry represents one such area,as digital transformation disrupts relationships between patients,healthcare professionals,and healthcare institutes.Patients and healthcare institutes lack a proficient tool to verify the credentials of medical professionals in a digital environment.Furthermore,healthcare professionals lack a tool where they are in control over their credentials.The first contribution of this paper is a proposal of a solution that leverages the private permissioned Hyperledger Fabric blockchain and smart contracts to provide a source of transparent trust for relationships within the healthcare industry.Second,we pave the ground for GDPR compliance by storing only the hash values on the blockchain.Third,we solve the problem of patient authentication by utilizing cryptographic techniques.Finally,we prove the usability of the proposed solution by implementing a user interface and creating a live deployment.
文摘Blockchain is gaining massive attention and has the potential to impact different types of record-keeping processes.It is one of the most innovative technologies potential enough to impact every industry from financial to educational institutes.Recently,consensus mechanisms have enabled distributed ledger technologies(DLTs)to find their applications and values in various sectors.A consensus algorithm is an essential element of blockchain networks.Consensus mechanisms function to ensure the transaction's validity,reliability,and authenticity in a peer-to-peer network.The consensus algorithm assures the authenticity of transactions in a trustless and distributed manner.Choosing the right consensus algorithm plays a crucial role in the performance of a blockchain application.In this paper,a detailed survey of different types of blockchain consensus algorithms that are popular and commonly used today is presented.
基金This work was supported in part by the NWO Aspasia(Grant 91716421)by the Maastricht York-Partnership Grant。
文摘Easy access to data is one of the main avenues to accelerate scientific research.As a key element of scientific innovations,data sharing allows the reproduction of results and helps prevent data fabrication,falsification,and misuse.Although the research benefits from data reuse are widely acknowledged,the data collections existing today are still kept in silos.Indeed,monitoring what happens to data once they have been handed to a third party is currently not feasible within the current data sharing practices.We propose a blockchain-based system to trace data collections and potentially create a more trustworthy data sharing process.In this paper,we present the LUCE(License accoUntability and CompliancE)architecture as a decentralized blockchain-based platform supporting data sharing and reuse.LUCE is designed to provide full transparency on what happens to the data after they are shared with third parties.The contributions of this work consist of i)the design of a decentralized data sharing solution with accountability and compliance by design and ii)the inclusion of a dynamic consent model for personalized data sharing preferences and for enabling legal compliance mechanisms.We test the scalability of the platform in a real-time environment where a growing number of users access and reuse different datasets.Compared to existing data sharing solutions,LUCE provides transparency over data sharing practices,enables data reuse,and supports regulatory requirements.The experimentation shows that the platform can be scaled for a large number of users.
文摘Identity management has been ripe for disruption over the past few years due to recurring incidents of data breaches that have led to personal information leaks and identity theft.The rise of blockchain technology has paved the way for the development of self-sovereign identity(SSI)—a new class of user-controlled resilient identity management systems that are enabled by distributed ledger technology.This paper examines how SSI management can be used in a public transportation sector that spans different operators in multiple countries.Specifically,the paper explores how a blockchain-based decentralized identity management system can draw on the SSI framework to provide high-level security and transparency for all involved parties in public transportation ecosystems.Accordingly,building on analyses of the existing public transportation ticketing solutions,we elicited requirements of a comparable system based on the SSI principles.Next,we developed a low-fidelity prototype to showcase how passengers can utilize standardized travel credentials that are valid across different transportation networks in Europe.The proposed system eliminates the need for multiple travel cards(i.e.,one for each transportation provider)and empowers individuals to have better control over the use of their identities while they utilize interoperable ticketing systems across Europe.Overall,building on the public transportation case,we offer a proof-of-concept that shows how individuals can better manage their identity credentials via the SSI framework.
文摘At present, there is an urgent need for blockchain interoperability technology to realize interconnection between various blockchains, data communication and value transfer between blockchains, so as to break the ‘value silo’ phenomenon of each blockchain. Firstly, it lists what people understand about the concept of interoperability. Secondly, it gives the key technical issues of cross-chain, including cross-chain mechanism, interoperability, eventual consistency, and universality. Then, the implementation of each cross-chain key technology is analyzed, including Hash-locking, two-way peg, notary schemes, relay chain scheme, cross-chain protocol, and global identity system. Immediately after that, five typical cross-chain systems are introduced and comparative analysis is made. In addition, two examples of cross-chain programmability and their analysis are given. Finally, the current state of cross-chain technology is summarized from two aspects: key technology implementation and cross-chain application enforcement. The cross-chain technology as a whole has formed a centralized fixed mechanism, as well as a trend of modular design, and some of the solutions to mature applications were established in the relevant standards organizations, and the cross-chain technology architecture tends to be unified, which is expected to accelerate the evolution of the open cross-chain network that supports the real needs of the interconnection of all chains.
文摘Threshold proxy re-encryption(PRE) authorizes the data access right of data subject to multiple proxies, who authorize the right again to delegatee to accomplish the end-to-end data encryption process from storage to authorization. Based on threshold PRE algorithm, in order to build a complete trusted data storage and authorization system, the four protocols, which are data access protocol, authorization proxy protocol, authorization proxy cancellation protocol and data reading authorization protocol, are defined completely. On that basis, an efficient data searching method is constructed by specifying the data delegatee. At last, to ensure the right to know of data, the audit log is processed with trusted data right confirmation based on distributed ledger technology. Meanwhile, a parallel data right confirmation processing method is defined based on hierarchical derivation algorithm of public and private key. In the end, the performance evaluation analysis of the protocol are given. Trusted data access and authorization protocol is convenient to build a complete data processing system on the premise of protecting data privacy based on public cloud storage system or distributed storage system.
