With the wide spread of Bitcoin,block chain serving as the building block of digital currency becomes a hot spot in industry and academia.Due to the decentration of network,the unforgeability of block data,etc.,block chain has attracted more and more attentions from financial institutions.The essential theory and core technique of block chain were surveyed,and the issues of management and security problems of block chain based applications were discussed.To help improve the block chain techniques is the goal.
In the current era of digitalization and networking,the demand for digital copyright transactions is increasing.The traditional centralized copyright protection system has series of problems such as high registration costs,long work acceptance times,and being vulnerable to tampering by saboteurs.Blockchain as a decentralized network structure and based on P2P network and cryptographic technology,which can establish trust relationship on the network by pure mathematics.Without relying on the middle platform,blockchain technology can naturally alleviate the above problems.With the help of self-regulatory,traceable and decentralized features of blockchain technology and digital copyright trading scenarios,a digital copyright trading system model was designed.The new system is based on the advanced permissioned blockchain provided by IBM.The implementation of copyright registration and copyright transaction can ensure the integrity and tamper-resistant of the information.Finally,the installation time of chain code deployment was tested.The results show that the system is simple to install and has low maintenance costs.Compared with the traditional trusted third party copyright authentication mechanism,the blockchain-based digital rights trading system has a short registration time,no registration fee,and better architecture security and scalability.
The value of block chain technology is proved by the success of Bitcoin. The characteristics, limitations and its chain structure Hash principle of block chain were analyzed, the applications of block chain technology were researched, the B2B+B2C supply chain each transaction subject transaction structure diagram and dynamic multi-center coordination authentication model based on block chain were proposed. Then the producing process of block chain in B2B+B2C supply chain electronic transaction with example was analyzed, and the facing problems that block chain spreading use in B2B+B2C supply chain enterprise were pointed out. The research results have proposed a new idea for the application of cryptography and block chain.
The rise of blockchain technology is a paradigm shift,which is similar to the rise of the Internet,and it has attracted wide attention.Blockchain has characteristics of decentralization,tamper-resistant,traceability and so on.The achievements of some papers about blockchain at home and abroad have been analysed in recent years,and the core technology principle of blockchain has been parsed.The application scenarios of blockchain were disscussed,such as financial services,credit management,tenure management,public network service and other fields.The existing problems in various application fields were pointed out.Some opinions on the development and application of blockchain were put forward,dedicated to blockchain and hoped to do contribution for the research about blockchain and its applications.
How to enhance the management of modern enterprises by blockchain technology has attracted more and more attention.ERP (enterprise resource planning) technology combined modern information technology with enterprise production process management,and effectively strengthened the work efficiency and management level of enterprises.But there were inherent pain points such as equipment security,data security,industrial control security,information leakage and so on.Aimed at the problems exposed by ERP system,a blockchain based framework mod el of ERP system proposed by taking advantage of the characteristics of decentralization,de-trust,openness and transparency,trusted database and traceability of blockchain.The key point is to solved the problem of credible and efficient data collaboration in the production and management process of enterprises.Combine with the incentive mechanism of blockchain,use token to strengthen collaborative management and improve efficiency,which provide a new idea for enterprise performance evaluation and assessment.
Combined blockchain technology with IoT applications,a blockchain-based IoT architecture was proposed,and a blockchain-based IoT identification method was designed.The equipment registration service process and the query service process based on the proposed IoT architecture were illustrated,and the security of the system was analyzed.Finally,based on the proposed network architecture and the identification method,the application in the smart home scenario was given.It can be seen from the two typical cases that the proposed solution can guarantee the security of various applications in the Internet of things.
Blockchain is a kind of distributed ledger technology that upgrades to a complete storage system by adding logic control functions such as intelligent contracts.With the changes of its classification,service mode and application requirements,the core technology forms of Blockchain show diversified development.In order to understand the Blockchain ecosystem thoroughly,a hierarchical technology architecture of Blockchain was proposed.Furthermore,each layer of blockchain was analyzed from the perspectives of basic principle,related technologies and research progress in-depth.Moreover,the technology selections and characteristics of typical Blockchain projects were summarized systematically.Finally,some application directions of blockchain frontiers,technology challenges and research prospects including Smart Cities and Industrial Internet were given.
Blockchain is a kind of distributed ledger technology with the characteristics of decentralization,security reliability,tamper-proof and programmable.The open and transparent feature of the blockchain system has seriously threatened the transaction privacy of users,and the corresponding privacy problem solution is designed for different application scenarios.Firstly,the basic working principle of block chain technology was introduced,and typical privacy issues was introduced in blockchain,such as transaction privacy and account privacy.Secondly,the existing typical blockchain privacy protection schemes were divided into three types:mixed-coin technology,cryptography technology and secure channel technology,and presents a comprehensive and comprehensive introduction to this three privacy protection schemes; Finally,the blockchain data privacy protection technology was analyzed,the application and development on IoT security were prospeted.
Based on the current status of Chinese credit information system,expounding the problems arising from the traditional credit information system structure,a credit system structure based on blockchain technology and two data transaction pattern and the technical framework of the credit data trading platform was proposed,It has the characteristics of decentralization,safe and credible,collective maintenance,and untampering.And the process of data transaction were expounded.To explore the advantage of application of blockchain in the credit and information industry:promote credit data sharing,improve the quality of supervision of the credit and information industry,ensure the privacy of the information subject,effectively improve the dimension of credit information.
To solve the privacy leakage problem in the process of identification by second generation residents’ ID card,the SM2 algorithm and the blockchain technology were adopted,and the dynamic password ,facial recognition and two-dimension code to modify the traditional identification method were combined to design a kind of identification agreement on mobile terminal.The study analyzed the efficiently and security of the agreement,which reflected that the agreement could guarantee users’ privacy when it provide high-efficient identification.
Aiming at the needs of edge computing for data privacy, the correctness of calculation results and the auditability of data processing, a privacy protection method for edge computing based on blockchain and federated learning was proposed, which can realize collaborative training with multiple devices at the edge of the network without a trusted environment and special hardware facilities.The blockchain was used to endow the edge computing with features such as tamper-proof and resistance to single-point-of-failure attacks, and the gradient verification and incentive mechanism were incorporated into the consensus protocol to encourage more local devices to honestly contribute computing power and data to the federated learning.For the potential privacy leakage problems caused by sharing model parameters, an adaptive differential privacy mechanism was designed to protect parameter privacy while reducing the impact of noise on the model accuracy, and moments accountant was used to accurately track the privacy loss during the training process.Experimental results show that the proposed method can resist 30% of poisoning attacks, and can achieve privacy protection with high model accuracy, and is suitable for edge computing scenarios that require high level of security and accuracy.
Non-fungible token (NFT) based on blockchain is a kind of digital asset ownership recorded on blockchain, which is unique, irreplaceable and indivisible.It has been widely used in collectibles, encrypted artworks and games.Firstly, the concepts, characteristics and development processes of NFT were mainly introduced, and its core elements and typical application fields were analyzes.The problems and risks faced by NFT in the aspects of property right, value, technology and supervision were also pointed out.After that, the related literatures on NFT were reviewed, and the research issues of NFT in value evaluation, transaction mode and pricing were proposed.Finally, the trend of NFT driven digital capitalization was prospected.
Road conditions early-warning scheme is effective solution to solve vehicle congestion and traffic accidents of VANET.The current traffic conditions in China as well as the development and application of VANET were analyzed.Combined with blockchain technology,a blockchain-based traffic conditions early-warning scheme for VANET was proposed.The Hyperledger Fabric alliance chain technology platform is used to simulate this scheme.The experimental results show that the scheme is reasonable and feasible.
Blockchain has the characteristics of decentralization,stability,security,and non-modifiability.With the further improvement and application of the blockchain technology,it will be connected with the traditional industries such as finance,medical treatment and logistics.This will radically change the existing operation modes in some industries and restructure a value network.An application of blockchain in the field of supply-chain finance was tried,and a supplychain finance service platform based on the blockchain technology was constructed.The platform combines blockchain technology with other traditional systems,providing a more convenient way of financing for all parties in the supply-chain,improving the transparency,traceability and security of the supply-chain.
The board voting is a scenario of anonymous voting on a particular group of individuals,which is strict with the identities of the participants.A board e-voting protocol based on the consortium blockchains was presented,which replaced the traditional trusted third party with the smart contract so as to reduce the system trust cost.It adopt a digital certificate-based identity mechanism to ensure that the voter's identity is legal.It adopt the blind signature based on elliptic curve technology to achieve the anonymity of voting.The security analysis shows that the proposed protocol can meet the requirements of unforgeability,anonymity and security etc,which is convenient and flexible to use.
Regarding the difficult key management and excessive communication overhead in the distributed group networks,KMSBoB-Key management schemes based on blockchain was proposed,featuring key management and transmitting procedure based on blockchain in distributed group networks.Meanwhile,the all-member mining process of blockchain and the MTI/CO protocol process were combined to establish a protocol of dynamically generated session key,so as to streamline key management strategies in cross-heterogeneous autonomous domains.According to simulation testing and result analysis,KMSBoB is safe and effective,with less communication overhead and higher expansibility than traditional key management schemes.
Blockchain is a peer-to-peer distributed ledger technology based on cryptography,However,open and transparent blockchain ledger,combined with sociological mining,data mining and other statistical methods,brings a major threat to user’s privacy.Therefore,privacy protection becomes a hot issue on the blockchain technology research.The existing privacy protection schemes were summarized,especially focusing on the zero-knowledge proof techniques.The technical challenges in applying zero-knowledge proof to blockchain privacy protection schemes were expounded and analyzed,and position solutions to these challenges were given.
Transnational and intercontinental electricity trading (TIET) is a fundamental enabling component and efficient method to the development of Global Energy Internet (GEI),which aims to build an energy model centered on electricity consumption.The problems faced by TIET was analyzed,and a transnational and intercontinental electricity market (TIEM) based on blockchain and token economics was proposed.The TIEM was divided into five components,and each component was described and modeled respectively.A scale-up power grid based IEEE 39-nodes system was used to analyze the proposed market.The simulation results show that TIEM based on blockchain and token economy can ensure the effective implementation of cross-regional and multi-agent electricity transactions,and also encourage the generation companies (GENCOs) to participate in electricity market with clean energy.
Circulation of big data is a key link in the value creation of data,but there are numerous problems to be solved.Blockchain is a distributed ledger technology,which can be applied in data circulation by its decentralizing and immutable property.The main idea of authorized deposit certificate,data traceability and smart contract using blockchain was discussed,and the overall architecture of data circulation by blockchain was proposed.Finally,some applications and other data security solutions were introduced.
Blockchain technology is a distributed data storage technology that is de-centralized,de-trusted,open and transparent.It can reduce the cost of trust and realize safe and reliable data interaction.However,attackers can easily obtain the transaction data stored in the public ledger,and may extract transaction rules and other privacy information from this data by applying big data analysis techniques.Firstly,the thread of attack of data analysis on blockchain transaction data was analyzed,and the attack methods based on data analysis were described.Then the privacy protection mechanism of transaction data which was represented by mixing mechanism was introduced,the basic principle of various mixing methods was described in brief,and the advantages and disadvantages of different mixing approaches for the problem of whether a central node was needed in the process of mixing were analyzed.In the end,the limitation of the existing technologies and envision the future directions on this topic was discussed.
In order to improve the difficulty of maintaining the static binding method when defending against ARP attacks,a defense method was designed with the features of low cost of defense and easy maintenance by using the idea of a blockchain technology.The blockchain structure had been improved,and the transaction index table structure had been designed to identify attacks and update data in a timely manner to prevent subsequent attacks.The content of the transaction index table was updated after the IP address was changed normally to ensure the correctness of the query.Analysis and experiments show that the blockchain-based defense method has the following merits:high security,guaranteeing the data is not tampered with,low cost of maintenance,and effective prevention against ARP spoofing attacks.
Recent researches on blockchain have been greatly concerned by academia and industry,while the communication based on TCP/IP protocol was not enough for broadcasting a large volume of data in blockchain technology.Therefore,a novel node model supporting push service for blockchain technology and a special procedure reading-writing the table of the node model were designed based on the named-data networking,which was a distributed network architecture supporting data transmission naturally.And then the information transmission architecture of blockchain technology via named-data networking was proposed.With the aggregation of the requests and data caching,this architecture could reduce the traffic redundancy and accelerate the communication speed.Meanwhile,a use case of bitcoin based on the proposed architecture was given,in order to better understand the architecture.A numerical simulation was used to verify the performance advantages of the proposed scheme.In addition,some related future research directions were presented.
Blockchain technology is a distributed data recording scheme to record all transactions or electronic behavior, namely public ledger technology. Blockchain technology has gradually caught attention of the public, causing widespread concern and discussion in the world with the features of distributed, decentralized and non fraud. The working theory of the blockchain and its application in the field of finance and non-finance were described. And the challenges and opportunities in the development of the blockchain technology were analyzed.
Blockchain could achieve trustworthy ledger management without central node.It has been successfully supporting financial applications such as Bitcoin.The essence of blockchain is trusted data management in an incompletely trusted environment.It has such features as decentralization,anti-tampering,strong consistency and integrity.On the other hand,blockchain also suffers the problem of weak data management functions,low performance and other issues.By comparing blockchain with traditional data management techniques and analyzing the three applications of blockchain beyond the financial fields,new research issues on blockchain were explored.The requirement for design and implementation of sharing database systems for specific application domains was discussed.The sharing database can be simply defined as a database that supports mission-critical applications,the sharing economic business model,and even itself is implemented in a sharing economy manner.
With the development of the mobile internet and IoT (internet of things),mass data are stored in the cyberspace.The network security and privacy are of great significance.The blockchain-based network security mechanism has the properties of decentralization,tamper-resistance,traceability,high availability and credibility,and can be applied to improve network security.The application of blockchain in the network security was explored.The main technologies and the future research direction of the blockchain-based network security mechanism were analyzed.Firstly,the blockchain-based data protection scheme was analyzed,which applied the tamper-resistance of the blockchain to improve the authenticity and reliability of data.Secondly,the blockchain-based IoT device management scheme was analyzed,which applied the blockchain to record and execute the device control instruction and improve the authority and communication of the IoT devices.Lastly,the blockchain-based domain name system was analyzed,which applied the decentralization of the blockchain to resist distributed denial of service effectively.
6G network not only explore higher communication rates but also combine with the emerging technologies such as cloud computing,edge computing,artificial intelligence,and big data,and use a new network architecture to achieve wider interconnection and interoperability across network and domains,and provide an intelligent,safe and efficient technical support for industrial Internet of things,smart cities,and intelligent transportation.Blockchain technology as a decentralized,open and transparent distributed ledger technology can provide strong security for 6G.The integration of blockchain technology and 6G network was studied.Firstly,the difference between 5G and 6G network and the challenges of 6G faced were given,and the research of blockchain technology in spectrum management,mobile edge computing and D2D communication was reviewed.Then,the integration of blockchain technology and 6G emerging network was explored.Thus,the technical challenges in terms of blockchain and the cloud-edge-device network,blockchain and federal learning,blockchain-based resource transactions,and lightweight blockchain for edge network were presented.The corresponding solutions were also given.
In view of the increasing number of people in the digital interaction process of direct or indirect disclosure of privacy issues,the establishment of a set of data security sharing system based on blockchain network,the access control algorithm based on ciphertext-policy attribute-based encryption and the homomorphic encryption algorithm provides reliable chain data sharing were mainly researched.Data sharing on chain architecture for data sharing on the chain was proposed.Finally,simulation experiments were carried out,and the results of experimental data were analyzed.The work effectively solves the problem of malicious parties using the transaction transparency of blockchain for data analysis and ensures the privacy security of user data in the sharing process.
Blockchain is a kind of decentralized distributed data storage technology.Blockchain can solve the disadvantages of the centralized data market,however,distributed data marketplaces also introduce the problems of security and privacy.Firstly,the current status from industry and progress from academia of the bid data marketplaces were reviewed,and then the required properties that a well developed blockchain based data marketplaces should satisfy were proposed.Based on these properties,a blockchain based data marketplace framework was proposed.Then the potential security and privacy problems in this framework were investigated,and the corresponding solutions for these problems were designed.Based on this framework,a data marketplace demonstration system was implemented and its feasibility and security were verified.
While the security of blockchain has been the central concern of both academia and industry since the very start, new security threats continue to emerge, which poses great risks to the blockchain ecosystem.A systematic study was conducted on the most state-of-the-art research on potential security issues of blockchain.Specifically, a taxonomy was developed by considering the blockchain framework as a four-layer system, and the analysis on the most recent attacks against security loopholes in each layer was provided.Countermeasures that can strengthen the blockchain were also discussed by highlighting their fundamental ideas and comparing different solutions.Finally, the forefront of research and potential directions of blockchain security were put forward to encourage further studies on the security of blockchain.
With the development of blockchain technology,more and more blockchain projects have appeared.Due to the closure property of the blockchain,different blockchains have become islands of value.The information interaction and value transfer problems between different blockchains need to be solved urgently.The cross-chain technology is to solve the cross-chain operation problems of assets and data between different chains.There are many attempts and developments on cross-chain technology in the past few years,and the major models of cross-chain include Hash lock,notary mechanism,side chain and relay technology,etc.The concept of each cross-chain technology was introduced,and the advantages and disadvantages of each cross-chain technology were summarized and analyzed.
Blockchain′s characteristics of non-temper and decentralization can be utilized to improve the data security and scalability of storage systems,called blockchain storage.These works that combine storage with blockchain technology,are mainly divided into three categories:decentralized storage systems based on blockchain,improve the performance of existing storage systems based on blockchain,and the underlying storage strategies of blockchain.These works were summarized,the current blockchain storage systems were compared,the main challenges that blockchain and storage being facing were discussed and its future development was forecasted.
Blockchain technology has the features of decentralization, high credibility, non-tampering and traceability, which can address the trust problem in traditional access control technology.Based on the implementation with blockchain, the unique advantages of applying blockchain to access control are analyzed from two aspects: based on transaction and based on smart contract.Based on the key issues in blockchain application, the current research progress is summarized from three key technologies: dynamic access control, blockchain space optimization, and privacy data protection.Based on the challenges faced by the current blockchain-based access control mechanism, five research prospects are proposed.
The big data oriented blockchain for trade clearing was introduced,including consensus,secure transmission of trading data storage,data search,encryption and decryption of trading data and trade clearing business.The analysis of the framework design on dismantlement and combination of the composite trading was emphasized,and the potential value and significant meaning of blockchain data on risk decision and assessment through the big data analysis were identified.
To cope with current problems of trusted services management in social internet of things (SIoT),such as high degree of centralization,non-transparent transactions,vulnerability and so on,a framework of trusted services management based on blockchain in SIoT was proposed.This framework established the trusted relationship between service requesters and service providers directly by using decentralization of blockchain,then it produced and managed new transactions through smart contracts to realize transparency and reduce the cost of management.At the same time,the consensus mechanism of blockchain could be used for verifying transactions and preventing malicious attacks in order to reduce network attacks and malicious node spoofing.Finally,the main challenges which the framework would face in actual constructions were analyzed.
In order to solve the problem that the security of traditional internet of vehicles devices is relatively low,which may threaten the privacy of users,a privacy protection scheme based on homomorphic encryption and block chain technology was proposed.This scheme added the authentication service composed of two level nodes to the proposed model to realize the permission control of roles in the model.In order to record the information of the internet of vehicles devices,a new block data structure based on homomorphic encryption (HEBDS) was proposed,which enabled the privacy data to be written into the block after being processed by the Paillier encryption algorithm,and then written into the blockchain network by the gateway node obtaining the accounting right.This scheme realized the data processing in ciphertext state,and made up for the shortage of all data disclosure in blockchain network.Through the analysis of the security of the scheme,it is proved that the scheme has the characteristics of unforgeability and privacy data security.Through homomorphic encryption of privacy data and upload to blockchain network,the scheme can distribute,share and calculate privacy data in ciphertext state,which can protect customer privacy more effectively than traditional internet of vehicles model.
To solve the problem that the blockchain-based traceability algorithm mainly used homomorphic encryption and zero-knowledge proof for privacy protection,making it difficult to achieve dynamic sharing of traceability information,a blockchain data traceability algorithm based on attribute encryption was proposed.In order to realize the dynamic protection of transaction privacy,the strategy update algorithm applicable to block chain was designed based on the CP-ABE scheme proposed by Waters to achieve dynamic protection of transaction privacy.In order to realize the dynamic update of the visibility about block content,based on the strategy update algorithm,the block structure was designed to achieve the dynamic update about the content visibility of the block.The security and experimental simulation analysis show that the proposed algorithm can realize the dynamic sharing of traceability information while completing the protection transaction privacy.
To improve the transparency and traceability of access control, a blockchain-based access control mechanism for data traceability and provenance was proposed.The proposed access control policy was transferred to the smart contract and deployed on the blockchain, and the access authorization evaluation was realized by executing the smart contract deployed on the blockchain to ensure the decentralization, transparency and traceability of the access control process.The manner of combining off-chain and on-chain was adopted, the object was stored in off-chain data server, and the object index was generated by the object storage address and hash value, and deployed on the object blockchain.The log of object access authorization and access were recorded in the log blockchain, any misbehavior was immutably recorded.The security analysis show that, the proposed mechanism achieve the properties of decentralization, transparency and traceability while ensuring the privacy of data.
The centralized resolution system of the domain name system (DNS) implies an unavoidable risk of abuse of power,a top-level domain may be deleted from the root zone.By analyzing the related work on the root zone decentralization,the most were mainly to deploy new root resolution services outside the current root servers,but not to decentralize the root zone data.A scheme to decentralize the root zone data was proposed,and the decentralization of root zone data distribution and analysis were achieved through a peer-to-peer coalition between national roots.Trust from peer-to-peer to collective,with features such as autonomy,openness,equality,and transparency,and implements a distributed consensus on root zone data through blockchain technology were transformed by the program,thereby ensuring root zone data consistency.
Blockchain technology has attracted wide attention in recent years,and many industries are trying to solve the reliability and security problems of traditional centralized schemes in information systems based on blockchain technology.However,the connection between the blockchain network and industry entities must rely on the Internet of things (IoT) technology.Therefore,combining the blockchain and IoT technology to solve the pain points of vertical industries is the current research hotspot.On the other hand,the development of IoT itself is also limited by the centralized architecture,and how to use the blockchain technology to solve the predicament of IoT is also an important issue.Although there are many blockchain related applications,some of them are actually not suitable for blockchain technology.Firstly,the proper logic of blockchain applications was discussed.Then suitable application scenarios of blockchain technology were introduced by typical case analysis.Finally,four common problems when combining blockchain and IoT were discussed.
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