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.
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.
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 is one kind of collective and decentralized database technology without trust among the nodes.In essence,it is a distributed database which has no delete and update operations.The technical principles of blockchain was introduced,its industry situations and existing problems were discussed,and related policy suggestions were proposed from government,industry association and academic institution.
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.
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.
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 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 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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
At present time,China is entering an important period of upgradation and transitionin agriculture,therefore,promoting smart agriculture development will be becoming the prior way with integration of modern information technology.Firstly,the current status of agriculture in China and the necessity of smart agriculture were analyzed,including possible blockchain application.Secondly,the connotation and its main trend for blockchain were briefly introduced.Thirdly,the main fields of blockchain application were summed up for smart agriculture.Finally,the prospects were set forth and some important suggestions were proposed for agricultural blockchain in future.
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 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.
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.
With the development of blockchain,huge storage space is needed to store all of blockchain data.In addition,data can’t be changed once it is packaged into the chain,and it may be possible for overdue data to take up large storage space.Firstly,a threshold ring signature scheme was improved,and then a deletable blockchain scheme based on the mechanism of proof of space (PoSpace) consensus was constructed.Most of nodes could sign and delete a block together when block data was overdue,and the overall structure of the blockchain was unchanged.Several experiments in a simulated environment were executed,and the results show that the proposed blockchain scheme has high efficiency in generating and delegating a block.Meanwhile,the deletion of a block doesn’t influence the storage and use of other blocks.
The theory of decentralized blockchain mechanism was studied,and a method of applying distributed block chain technology to manage demand response planning in smart grid environment was proposed.This method was based on the blockchain distributed ledger accounting tamper-proof technology,which stored the energy consumption information collected from the intelligent metering devices of the IoT,and defined the self-executing intelligent contract at each consumer level in a programmatic way to ensure the flexibility of transactions.Blockchain distributed technologies provided incentives or penalties to balance energy demand with grid energy production rules.Consensus-based validation would be used to validate demand response plans and provide appropriate financial settlement for flexible suppliers.The results show that the power demand side management based on blockchain distributed technology can be used to match energy demand and production under the condition of smart grid,with high accuracy of demand response signal,but less flexibility required for convergence.
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.
Blockchain is a decentralized architecture emerging with cryptocurrencies,which is credible and robust.A network covert channel model in blockchain environment was proposed for the first time,which was anti-interference,anti-tamper modification,multi-line communication,receiver anonymity and line independence.The shortcomings of network covert channel in existing network environment could be tackled by the new type of network covert channel,such as characteristic defect.etc.Firstly,A network covert channel model in blockchain environment was presented by formal method,its anti-interference and anti-tamper modification was proved.Then,a blockchain network covert channel scenario using service operation interval time was presented.Finally,the undetectability,robustness and rate of the blockchain network covert channel evaluation vectors was proposed.A theoretical foundation was laid for the practicality of the new type of network covert channel in blockchain.
A decentralized credit system was proposed and its construction application was given.Decentralized credit system could be constructed by expanding the transaction structure of “digital currency commodity” based on block chain,expanding the function of consensus protocol and adding specific accounts.Also,the decentralized credit system was applied to the PKI enhancement and supervision system IKP so that IKP system did not need global fund in operation.Moreover,by introducing the hierarchical “virtual currency commodity” supply adjustment mechanism in the decentralized credit system to alleviate the difficulty of regulating the “virtual currency commodity” supply of “digital currency commodity” based on block chain,the precise “virtual currency commodity” supply regulation can be achieved.
In a searchable encryption scheme,whether it is a cloud server or a user,it may be deceptive.In order to solve the security problem,the definition of fairness security was given and a new searchable encryption scheme based on blockchain was proposed.Through the third-party trusted authority to verify the consistency of data during data transmission,the complete verification results were recorded on the blockchain to prevent tampering,and it could make all the related entities to reach the consistent security consensus and achieve the fairness security.The security and complexity analysis show that the proposed searchable encryption scheme was feasible.If it is combined with a searchable encryption scheme with its searched results verifiable,the proposed scheme can be effectively improved to be a blockchain-based searchable encryption scheme with its searched results verifiable and its security will be more strengthened.
The blockchain is essentially a distributed database that can be safely updated without the need for third-party intermediaries.The blockchain technology is introduced into the 6G cellular mobile communication system to ensure the privacy of users,reduce the cost of resource allocation and communication services,and support different distributed applications.In order to realize the organic combination of mobile communication and blockchain technology,it is predicted to be one of the key technologies of 6G cellular mobile communication.From the blockchain combined with internet of things (IoT),edge computing,spectrum allocation,interference management,a detailed introduction was introduced,and the latest research progress of international academic circles in this direction was expounded in recent years,and on this basis,the development trend of blockchain technology in 6G cellular mobile communication was further prospected.
With the frequent occurrence of network security issues,the industry had not satisfied the patch-based external security solution,and it was hoped that the endogenous security could be realized from the network architecture layer.The decentralized trustworthy network architecture was proposed.Based on the research of the security of existing network underlying protocol,a trustworthy network architecture based on decentralization technology was proposed,such as blockchain technology,which could effectively solve the problem of lack of endogenous security in existing networks.Layers implement network security to avoid malicious network attacks or network failures caused by configuration errors.
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.
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.
With the development of mobile communication technology towards marginalization and distributed structure,the traditional network security method of external border protection will be faced with more and more challenges.The emerging network security accidents also show that it is necessary to grow self-adaptive,independent and self-growing security capabilities from the information system,that is,endogenous security.Blockchain,as a de-centralized shared ledger and database,has the characteristics of decentralization,immutability,leaving traces throughout,traceability,collective maintenance,openness and transparency,etc.,which can greatly meet the needs of endogenous security design.Therefore,the necessity and demand of endogenous security was described,then the blockchain technology as an important means to realize endogenous security was introduced,the main research progress,difficulties and challenges faced by blockchain were analyzed,and the future research direction and oppor-tunities were put forward.
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