Recently,the China National Intellectual Property Administration released the"List of Enterprises Approved to Use the Geographical Indication Logo."The"Wujiang Silk"geographical indication logo has...Recently,the China National Intellectual Property Administration released the"List of Enterprises Approved to Use the Geographical Indication Logo."The"Wujiang Silk"geographical indication logo has been renewed and launched.This official approval serves to distinguish and celebrate the quality and cultural heritage of Shengze silk,and the use of this symbol is a testament to that distinction.Three enterprises from Shengze have been approved to use the logo:Saint Joy,Huajia Silk,and Xinmin Silk.展开更多
The purpose of the covert communication scheme is to conceal the communication behavior entirely.In such schemes,the sender and receiver rely on secret keys to establish a covert channel.However,conventional key excha...The purpose of the covert communication scheme is to conceal the communication behavior entirely.In such schemes,the sender and receiver rely on secret keys to establish a covert channel.However,conventional key exchange protocols would expose the key exchange process between them.An adversary who observes the key exchange would be aware of the existence of communication behavior.The keys used in covert communication are not suitable to be generated through conventional key exchange schemes.To address this,we propose a blockchain-based covert elliptic-curve Diffie-Hellman key exchange scheme(BCDH)to conceal the process of the key exchange in blockchain transactions.Following a straightforward setup,BCDH allows the sender and receiver to covertly exchange a secret key on a blockchain without direct communication.Furthermore,we expand the BCDH approach to operate across multiple blockchains,further enhancing its covertness and stability.We analyze BCDH from several perspectives,including covertness,security,randomness,etc.Additionally,we implement a prototype of BCDH on the Ethereum platform to assess its feasibility and performance.Our evaluation demonstrates that BCDH is efficient and well-suited for real-world applications.展开更多
Electronic auctions(e-auctions)remove the physical limitations of traditional auctions and bring this mechanism to the general public.However,most e-auction schemes involve a trusted auctioneer,which is not always cre...Electronic auctions(e-auctions)remove the physical limitations of traditional auctions and bring this mechanism to the general public.However,most e-auction schemes involve a trusted auctioneer,which is not always credible in practice.Some studies have applied cryptography tools to solve this problem by distributing trust,but they ignore the existence of collusion.In this paper,a blockchain-based Privacy-Preserving and Collusion-Resistant scheme(PPCR)for double auctions is proposed by employing both cryptography and blockchain technology,which is the first decentralized and collusion-resistant double auction scheme that guarantees bidder anonymity and bid privacy.A two-server-based auction framework is designed to support off-chain allocation with privacy preservation and on-chain dispute resolution for collusion resistance.A Dispute Resolution agreement(DR)is provided to the auctioneer to prove that they have conducted the auction correctly and the result is fair and correct.In addition,a Concise Dispute Resolution protocol(CDR)is designed to handle situations where the number of accused winners is small,significantly reducing the computation cost of dispute resolution.Extensive experimental results confirm that PPCR can indeed achieve efficient collusion resistance and verifiability of auction results with low on-chain and off-chain computational overhead.展开更多
As the world grapples with increasing environmental challenges,innovative technologies are essential for promoting sustainability and accountability.This study examined the impact of environmental performance indices(...As the world grapples with increasing environmental challenges,innovative technologies are essential for promoting sustainability and accountability.This study examined the impact of environmental performance indices(EPIs)on the growth and investment trends of blockchain-based sustainability-focused companies in 15 countries(Belgium,Czechia,Denmark,Estonia,Finland,France,Germany,Italy,Norway,Poland,Sweden,Spain,Switzerland,the United Kingdom,and the United States)from Europe and America during 2010-2022.This study used the negative binomial regression model to assess the relationship between EPIs and blockchain-based sustainability-focused companies based on the data from the CrunchBase and EarthData.Results indicated that in ecosystem vitality,national terrestrial biome protection efforts were negatively correlated the formation of blockchain-based sustainability-focused companies,while global terrestrial biome protection efforts and marine protected areas had a positive impact on the formation of these companies and the number of funding rounds.In environmental health,PM2.5 exposure had a positive impact on the number of funding rounds.Conversely,pollutants such as sulfur dioxide(SO_(2))and ocean plastics deterred the formation of blockchain-based sustainability-focused companies and reduced the number of funding rounds.In climate change performance,adjusted emission growth rate for carbon dioxide(CO_(2)),adjusted emission growth rate for F-gases,and adjusted emission growth rate for black carbon had a significantly positive impact on the formation of blockchain-based sustainability-focused companies.Conversely,adjusted emission growth rate for Nitrous Oxide(N_(2)O)and projected greenhouse gas emissions in 2050 negatively affected the formation of these companies.These findings highlight the dual role of EPIs as driving factors and barriers in the development and investment of blockchain-based sustainability-focused companies in countries from Europe and America.展开更多
Blockchain has proven to be an emerging technology in the digital world, changing the way everyone thinks about data security and bringing efficiency to several industries. It has already been applied to a wide range ...Blockchain has proven to be an emerging technology in the digital world, changing the way everyone thinks about data security and bringing efficiency to several industries. It has already been applied to a wide range of applications, from financial services and supply chain management to voting systems and identity verification. An organization must verify its candidates before selecting them. Choosing an unqualified candidate can ruin an organization’s reputation. In this paper, a blockchain-based academic certificate authentication system will be used to ensure authenticity and make the assertion of the decentralized system secure. However, the system will generate, authenticate and make corrections on academic certificates. Ultimately, some blockchain-based authentication systems already exist, they can’t correct any errors that occur during generation. A blockchain-based certificate authentication system was built using blockchain technology. Where admin could generate, authenticate and correct the certificate if necessary. The admin can also check how many times a certificate has been modified. Other users can only check the authenticity of the certificates. We’re using two blockchains to enable corrections. Blockchain technology can successfully implement a certificate authentication system. This system will eliminate doubts about the authenticity of certificates, provide fast responses, and ensure reliable and secure storage. The proposed system will help in many ways, such as providing a user-friendly university admission, and smooth job hiring process, etc. In conclusion, our proposed system can permanently eradicate certificate forgeries and create and promote trust in society.展开更多
Currently,digital certificate systems based on blockchain have been extensively developed and adopted.However,most of them do not take into account the certificate quality.To evaluate the credibility of certificates i...Currently,digital certificate systems based on blockchain have been extensively developed and adopted.However,most of them do not take into account the certificate quality.To evaluate the credibility of certificates issued by educational institutions,we propose a novel blockchain-based system with credit self-adjustment(BC-CS).In BC-CS,employers can provide feedback according to the performances of their employees(i.e.,students)holding different certificates.Based on the feedback,BC-CS automatically adjusts the certificate credits by using our proposed credit self-adjustment algorithm.To verify the feasibility of our proposed system,a decentralized application prototype has been developed on an Ethereum network.Experimental results demonstrate that the proposed system can fully support multistep accreditation and automatic adjustment for certificate credit.展开更多
Traditional email systems can only achieve one-way communication,which means only the receiver is allowed to search for emails on the email server.In this paper,we propose a blockchain-based certificateless bidirectio...Traditional email systems can only achieve one-way communication,which means only the receiver is allowed to search for emails on the email server.In this paper,we propose a blockchain-based certificateless bidirectional authenticated searchable encryption model for a cloud email system named certificateless authenticated bidirectional searchable encryption(CL-BSE)by combining the storage function of cloud server with the communication function of email server.In the new model,not only can the data receiver search for the relevant content by generating its own trapdoor,but the data owner also can retrieve the content in the same way.Meanwhile,there are dual authentication functions in our model.First,during encryption,the data owner uses the private key to authenticate their identity,ensuring that only legal owner can generate the keyword ciphertext.Second,the blockchain verifies the data owner’s identity by the received ciphertext,allowing only authorized members to store their data in the server and avoiding unnecessary storage space consumption.We obtain a formal definition of CL-BSE and formulate a specific scheme from the new system model.Then the security of the scheme is analyzed based on the formalized security model.The results demonstrate that the scheme achieves multikeyword ciphertext indistinguishability andmulti-keyword trapdoor privacy against any adversary simultaneously.In addition,performance evaluation shows that the new scheme has higher computational and communication efficiency by comparing it with some existing ones.展开更多
Forest certification is considered to be complementary to forest management policies and takes a significant effect on forest product trade. In recent decade, it has been followed with interest and approved by governm...Forest certification is considered to be complementary to forest management policies and takes a significant effect on forest product trade. In recent decade, it has been followed with interest and approved by governments and forestry de-partments in the world. This paper analyzes the influence of forest certification on forest product trade in the world, including the interest in certification in exporting countries and importing countries, trade flow and business competition, and the demands for Certified Forest Products (CFPs) and also discusses the influence of forest certification on forest product trade in China.展开更多
Objective: To establish an evaluation index system for the first-time certification of diabetes specialist nurses in line with the clinical nursing practice in China, and to provide a reference basis for government ad...Objective: To establish an evaluation index system for the first-time certification of diabetes specialist nurses in line with the clinical nursing practice in China, and to provide a reference basis for government administrations and hospitals to formulate unified standards. Methods: After the research team has determined the theme, it will consult the development of A) specialist nursing through the library, Internet and electronic literature database;B) the history of the development of specialist nurses in diabetes and other fields;C) the selection criteria of specialist nurses;D) the training of specialist nurses system, assessment method;E) Specialist nurse certification body, evaluation standards and certification standards and other related documents, literature, books and report materials. The author established the preliminary index system through literature review, specialist interview and group discussion and used Delphi method to organize three rounds of 30 experts’ consultations. Results: A first certification evaluation index system including 8 fundamental indicators, 5 first-level indicators, 19 second-level indicators and 99 third-level indicators was constructed for diabetes nurses. Conclusion: The results of three rounds of expert consultation and demonstration are reliable, and the constructed index system is suitable for comprehensive evaluation of diabetes specialist nurses, which provides a basis for the effective management of nursing resources.展开更多
The development strategy of the certification technology on engine bird ingestion is proposed after reviewing the development history of engine bird ingestion certification in developed Western countries,and analyzing...The development strategy of the certification technology on engine bird ingestion is proposed after reviewing the development history of engine bird ingestion certification in developed Western countries,and analyzing technical characteristics during different developing periods.Moreover,the main issues of bird ingestion certification technology,development program and strategy for the turbofan engines industry are addressed in detail.Finally,the relevant technique development is investigated and the main objects of bird ingestion certification technology for the turbofan engines are summarized and concluded.展开更多
Smart contract has been the core of blockchain systems and other blockchain-based systems since Blockchain 2.0.Various operations on blockchain are performed through the invocation and execution of smart contracts.Thi...Smart contract has been the core of blockchain systems and other blockchain-based systems since Blockchain 2.0.Various operations on blockchain are performed through the invocation and execution of smart contracts.This leads to extensive combinations between blockchain,smart contract,Internet of Things(IoT)and Cyber-Physical System(CPS)applications,and then many blockchain-based IoT or CPS applications emerge to provide multiple benefits to the economy and society.In this case,obtaining a better understanding of smart contracts will contribute to the easier operation,higher efficiency and stronger security of those blockchain-based systems and applications.Many existing studies on smart contract analysis are based on similarity calculation and smart contract classification.However,smart contract is a piece of code with special characteristics and most of smart contracts are stored without any category labels,which leads to difficulties of smart contract classification.As the back end of a blockchain-based Decentralized Application(DApp)is one or several smart contracts,DApps with labeled categories and open source codes are applied to achieve a supervised smart contract classification.A three-phase approach is proposed to categorize DApps based on various data features.In this approach,5,659 DApps with smart contract source codes and pre-tagged categories are first obtained based on massive collected DApps and smart contracts from Ethereum,State of the DApps and DappRadar.Then feature extraction and construction methods are designed to form multi-feature vectors that could present the major characteristics of DApps.Finally,a fused classification model consisting of KNN,XGBoost and random forests is applied to the multi-feature vectors of all DApps for performing DApp classification.The experimental results show that the method is effective.In addition,some positive correlations between feature variables and categories,as well as several user behavior patterns of DApp calls,are found in this paper.展开更多
This paper theoretically analyzes a deficiency of the existing scheme, and proposes a distributed multi-hop certification authority scheme for mobile Ad Hoc networks. In our design, we distribute the certification aut...This paper theoretically analyzes a deficiency of the existing scheme, and proposes a distributed multi-hop certification authority scheme for mobile Ad Hoc networks. In our design, we distribute the certification authority functions through a threshold secret sharing mechanism, in which each node holds a secret share and multiple nodes jointly provide complete services. Certification authority is not limited in a local neighborhood but can be completed within multi-hop location. In addition, we replace broadcast by multicast to improve system performance and reduce communication overhead. This paper resolves some technical problems of ubiquitous certification authority services, and presents a wieldy multi-hop certification authority algorithm. Simulation results confirm the availability and effectiveness of our design.展开更多
Forest sustainability is the foundation of forestry and modern forest management. Originally the central concept was sustained-yield and maximum timber production and then multiple-use and other non-timber values gain...Forest sustainability is the foundation of forestry and modern forest management. Originally the central concept was sustained-yield and maximum timber production and then multiple-use and other non-timber values gained importance. After the Rio Conference and development of the Montréal Process in the early 1990’s, forest sustainability rapidly gained importance and various forest certification schemes developed to certify forest products that were grown using sustainable forest management. Forest sustainability and forest certification have become critical topics in forestry curricula. The American Tree Farm System is one of the important North American forest certification organizations. Modern forestry curricula often include a capstone course where forest management plans are developed. We describe a capstone course at Clemson University under development that uses the management standards and management plan template of the American Tree Farm System as a framework for students to develop actual forest management plans for local forest owners. The material is integrated into a series of four courses leading up to the capstone course. The course offered a hands-on approach for students to create management plans using actual certification standards and the system’s management plan template. In addition, students received specialized training to qualify as auditors for the certification system. This is an example of forest sustainability being integrated into the forestry curriculum.展开更多
Distributed certification via threshold cryptography is much more secu re than other ways to protect certification authority (CA) 's private key,and c an tolerate some intrusions. As the original system such as IT...Distributed certification via threshold cryptography is much more secu re than other ways to protect certification authority (CA) 's private key,and c an tolerate some intrusions. As the original system such as ITTC,etc.,is unsaf e ,inefficient and impracitcal in actual network environment,this paper brings u p a new distributed certification scheme,which although it generates key shares concentratively,it updates key shares distributedly,and so,avoids single-po in t failure like ITTC. It not only enhances robustness with Feldman verification and SSL protocol,but can also change the threshold (t,k) flexibly and robu stly,and so,is much more practical. In this work,the authors implement the prototype sy stem of the new scheme and test and analyze its performance.展开更多
On weekends,Ms.Ran,who works in the Internet industry,goes to the Beijing Country Fair to buy vegetables,fruits and yoghourt."Before when I bought fruits at the stalls along the streets,I always asked whether the...On weekends,Ms.Ran,who works in the Internet industry,goes to the Beijing Country Fair to buy vegetables,fruits and yoghourt."Before when I bought fruits at the stalls along the streets,I always asked whether the fruit is suitable for pregnant women,"said Ms.Ran.She tried to learn if the vendor would admit the fruits had much pesticide residue,展开更多
Smart parks serve as integral components of smart cities,where they play a pivotal role in the process of urban modernization.The demand for cross-domain cooperation among smart devices from various parks has witnesse...Smart parks serve as integral components of smart cities,where they play a pivotal role in the process of urban modernization.The demand for cross-domain cooperation among smart devices from various parks has witnessed a significant increase.To ensure secure communication,device identities must undergo authentication.The existing cross-domain authentication schemes face issues such as complex authentication paths and high certificate management costs for devices,making it impractical for resource-constrained devices.This paper proposes a blockchain-based lightweight and efficient cross-domain authentication protocol for smart parks,which simplifies the authentication interaction and requires every device to maintain only one certificate.To enhance cross-domain cooperation flexibility,a comprehensive certificate revocation mechanism is presented,significantly reducing certificate management costs while ensuring efficient and secure identity authentication.When a park needs to revoke access permissions of several cooperative partners,the revocation of numerous cross-domain certificates can be accomplished with a single blockchain write operation.The security analysis and experimental results demonstrate the security and effectiveness of our scheme.展开更多
According to the investigation results of 70 green food enterprises in Sichuan Province,the strategic targets of enterprises implementing green food certification are discussed by borrowing ideas from the Balanced Sco...According to the investigation results of 70 green food enterprises in Sichuan Province,the strategic targets of enterprises implementing green food certification are discussed by borrowing ideas from the Balanced Score Card.Balanced Score Card index system is selected and improved according to the changes of enterprises before and after implementing the green food certification system.Then,the performance evaluation index system of enterprises implementing green food certification is established.This index system has five strategic directions of finance,customer,internal management,social ecology,and learning and growth,and has 11 strategic targets,such as increasing operating profit,expanding market,improving the quality of staff,improving the production technology level,enhancing the core competence of enterprises,ensuring food safety,improving the physical quality of human,and protecting ecological environment.According to the principles of guidance,scientificity,comparability,feasibility,and significance,a total of 24 evaluation indices are established,including the change of product cost,change of product sales revenue,change of profit rate,change of return on investment,change of internal and external lost cost,change of the proportion of certified products in total sales and so on.展开更多
Since the middle 1990s, ecotourism certification has been given more and more attention to around the world.As a developing country with abundant ecotourism products, it is necessary for China to adopt certification t...Since the middle 1990s, ecotourism certification has been given more and more attention to around the world.As a developing country with abundant ecotourism products, it is necessary for China to adopt certification to ensuresustainable development of ecotourism. But there are few products certificated until now in China. After reviewing thetrend of ecotourism certification in the world and summarizing its theory and method, this paper analyzes the progressand prospect of ecotourism certification in China, and concludes that certification in China is necessary and promising.展开更多
We explore the organizational, environmental, and economic effects of sustainable forest management （FM） certification by Smart- Wood （SW）, one of the certification bodies accredited by the Forest Stewardship Coun...We explore the organizational, environmental, and economic effects of sustainable forest management （FM） certification by Smart- Wood （SW）, one of the certification bodies accredited by the Forest Stewardship Council （FSC） to carry out certification in Japan. We closely investigated three enterprises： the Yusuhara Forest Owners＇ Cooperative, Yamanashi Prefectural Forest, and Ryujin-mura Forest Owners＇ Coopera- tive. Interviews with representatives of these entities provided crucial empirical information regarding the influence of certification on envi- ronmental assessment, rare-species protection, landscape-management planning, management objectives, and forest supervision. Attainment of FM status improved environmental awareness and engendered positive changes in assessing and managing forests and other natural resources but simultaneously imposed heavier economic costs.展开更多
文摘Recently,the China National Intellectual Property Administration released the"List of Enterprises Approved to Use the Geographical Indication Logo."The"Wujiang Silk"geographical indication logo has been renewed and launched.This official approval serves to distinguish and celebrate the quality and cultural heritage of Shengze silk,and the use of this symbol is a testament to that distinction.Three enterprises from Shengze have been approved to use the logo:Saint Joy,Huajia Silk,and Xinmin Silk.
文摘The purpose of the covert communication scheme is to conceal the communication behavior entirely.In such schemes,the sender and receiver rely on secret keys to establish a covert channel.However,conventional key exchange protocols would expose the key exchange process between them.An adversary who observes the key exchange would be aware of the existence of communication behavior.The keys used in covert communication are not suitable to be generated through conventional key exchange schemes.To address this,we propose a blockchain-based covert elliptic-curve Diffie-Hellman key exchange scheme(BCDH)to conceal the process of the key exchange in blockchain transactions.Following a straightforward setup,BCDH allows the sender and receiver to covertly exchange a secret key on a blockchain without direct communication.Furthermore,we expand the BCDH approach to operate across multiple blockchains,further enhancing its covertness and stability.We analyze BCDH from several perspectives,including covertness,security,randomness,etc.Additionally,we implement a prototype of BCDH on the Ethereum platform to assess its feasibility and performance.Our evaluation demonstrates that BCDH is efficient and well-suited for real-world applications.
基金supported by the National Key R&D Program of China (No.2020YFB1005500)the Leading-edge Technology Program of Jiangsu Natural Science Foundation (No.BK20202001)+1 种基金the Fundamental Research Funds for the Central Universities (No.XJSJ23040)the Postdoctoral Science Foundation of Jiangsu Province (No.2021K596C)。
文摘Electronic auctions(e-auctions)remove the physical limitations of traditional auctions and bring this mechanism to the general public.However,most e-auction schemes involve a trusted auctioneer,which is not always credible in practice.Some studies have applied cryptography tools to solve this problem by distributing trust,but they ignore the existence of collusion.In this paper,a blockchain-based Privacy-Preserving and Collusion-Resistant scheme(PPCR)for double auctions is proposed by employing both cryptography and blockchain technology,which is the first decentralized and collusion-resistant double auction scheme that guarantees bidder anonymity and bid privacy.A two-server-based auction framework is designed to support off-chain allocation with privacy preservation and on-chain dispute resolution for collusion resistance.A Dispute Resolution agreement(DR)is provided to the auctioneer to prove that they have conducted the auction correctly and the result is fair and correct.In addition,a Concise Dispute Resolution protocol(CDR)is designed to handle situations where the number of accused winners is small,significantly reducing the computation cost of dispute resolution.Extensive experimental results confirm that PPCR can indeed achieve efficient collusion resistance and verifiability of auction results with low on-chain and off-chain computational overhead.
文摘As the world grapples with increasing environmental challenges,innovative technologies are essential for promoting sustainability and accountability.This study examined the impact of environmental performance indices(EPIs)on the growth and investment trends of blockchain-based sustainability-focused companies in 15 countries(Belgium,Czechia,Denmark,Estonia,Finland,France,Germany,Italy,Norway,Poland,Sweden,Spain,Switzerland,the United Kingdom,and the United States)from Europe and America during 2010-2022.This study used the negative binomial regression model to assess the relationship between EPIs and blockchain-based sustainability-focused companies based on the data from the CrunchBase and EarthData.Results indicated that in ecosystem vitality,national terrestrial biome protection efforts were negatively correlated the formation of blockchain-based sustainability-focused companies,while global terrestrial biome protection efforts and marine protected areas had a positive impact on the formation of these companies and the number of funding rounds.In environmental health,PM2.5 exposure had a positive impact on the number of funding rounds.Conversely,pollutants such as sulfur dioxide(SO_(2))and ocean plastics deterred the formation of blockchain-based sustainability-focused companies and reduced the number of funding rounds.In climate change performance,adjusted emission growth rate for carbon dioxide(CO_(2)),adjusted emission growth rate for F-gases,and adjusted emission growth rate for black carbon had a significantly positive impact on the formation of blockchain-based sustainability-focused companies.Conversely,adjusted emission growth rate for Nitrous Oxide(N_(2)O)and projected greenhouse gas emissions in 2050 negatively affected the formation of these companies.These findings highlight the dual role of EPIs as driving factors and barriers in the development and investment of blockchain-based sustainability-focused companies in countries from Europe and America.
文摘Blockchain has proven to be an emerging technology in the digital world, changing the way everyone thinks about data security and bringing efficiency to several industries. It has already been applied to a wide range of applications, from financial services and supply chain management to voting systems and identity verification. An organization must verify its candidates before selecting them. Choosing an unqualified candidate can ruin an organization’s reputation. In this paper, a blockchain-based academic certificate authentication system will be used to ensure authenticity and make the assertion of the decentralized system secure. However, the system will generate, authenticate and make corrections on academic certificates. Ultimately, some blockchain-based authentication systems already exist, they can’t correct any errors that occur during generation. A blockchain-based certificate authentication system was built using blockchain technology. Where admin could generate, authenticate and correct the certificate if necessary. The admin can also check how many times a certificate has been modified. Other users can only check the authenticity of the certificates. We’re using two blockchains to enable corrections. Blockchain technology can successfully implement a certificate authentication system. This system will eliminate doubts about the authenticity of certificates, provide fast responses, and ensure reliable and secure storage. The proposed system will help in many ways, such as providing a user-friendly university admission, and smooth job hiring process, etc. In conclusion, our proposed system can permanently eradicate certificate forgeries and create and promote trust in society.
文摘Currently,digital certificate systems based on blockchain have been extensively developed and adopted.However,most of them do not take into account the certificate quality.To evaluate the credibility of certificates issued by educational institutions,we propose a novel blockchain-based system with credit self-adjustment(BC-CS).In BC-CS,employers can provide feedback according to the performances of their employees(i.e.,students)holding different certificates.Based on the feedback,BC-CS automatically adjusts the certificate credits by using our proposed credit self-adjustment algorithm.To verify the feasibility of our proposed system,a decentralized application prototype has been developed on an Ethereum network.Experimental results demonstrate that the proposed system can fully support multistep accreditation and automatic adjustment for certificate credit.
基金supported by the National Natural Science Foundation of China(Nos.62172337,62241207)Key Project of GansuNatural Science Foundation(No.23JRRA685).
文摘Traditional email systems can only achieve one-way communication,which means only the receiver is allowed to search for emails on the email server.In this paper,we propose a blockchain-based certificateless bidirectional authenticated searchable encryption model for a cloud email system named certificateless authenticated bidirectional searchable encryption(CL-BSE)by combining the storage function of cloud server with the communication function of email server.In the new model,not only can the data receiver search for the relevant content by generating its own trapdoor,but the data owner also can retrieve the content in the same way.Meanwhile,there are dual authentication functions in our model.First,during encryption,the data owner uses the private key to authenticate their identity,ensuring that only legal owner can generate the keyword ciphertext.Second,the blockchain verifies the data owner’s identity by the received ciphertext,allowing only authorized members to store their data in the server and avoiding unnecessary storage space consumption.We obtain a formal definition of CL-BSE and formulate a specific scheme from the new system model.Then the security of the scheme is analyzed based on the formalized security model.The results demonstrate that the scheme achieves multikeyword ciphertext indistinguishability andmulti-keyword trapdoor privacy against any adversary simultaneously.In addition,performance evaluation shows that the new scheme has higher computational and communication efficiency by comparing it with some existing ones.
文摘Forest certification is considered to be complementary to forest management policies and takes a significant effect on forest product trade. In recent decade, it has been followed with interest and approved by governments and forestry de-partments in the world. This paper analyzes the influence of forest certification on forest product trade in the world, including the interest in certification in exporting countries and importing countries, trade flow and business competition, and the demands for Certified Forest Products (CFPs) and also discusses the influence of forest certification on forest product trade in China.
文摘Objective: To establish an evaluation index system for the first-time certification of diabetes specialist nurses in line with the clinical nursing practice in China, and to provide a reference basis for government administrations and hospitals to formulate unified standards. Methods: After the research team has determined the theme, it will consult the development of A) specialist nursing through the library, Internet and electronic literature database;B) the history of the development of specialist nurses in diabetes and other fields;C) the selection criteria of specialist nurses;D) the training of specialist nurses system, assessment method;E) Specialist nurse certification body, evaluation standards and certification standards and other related documents, literature, books and report materials. The author established the preliminary index system through literature review, specialist interview and group discussion and used Delphi method to organize three rounds of 30 experts’ consultations. Results: A first certification evaluation index system including 8 fundamental indicators, 5 first-level indicators, 19 second-level indicators and 99 third-level indicators was constructed for diabetes nurses. Conclusion: The results of three rounds of expert consultation and demonstration are reliable, and the constructed index system is suitable for comprehensive evaluation of diabetes specialist nurses, which provides a basis for the effective management of nursing resources.
文摘The development strategy of the certification technology on engine bird ingestion is proposed after reviewing the development history of engine bird ingestion certification in developed Western countries,and analyzing technical characteristics during different developing periods.Moreover,the main issues of bird ingestion certification technology,development program and strategy for the turbofan engines industry are addressed in detail.Finally,the relevant technique development is investigated and the main objects of bird ingestion certification technology for the turbofan engines are summarized and concluded.
基金supported by the National Natural Science Foundation of China(62032025,62002393)the Technology Program of Guangzhou,China(202103050004).
文摘Smart contract has been the core of blockchain systems and other blockchain-based systems since Blockchain 2.0.Various operations on blockchain are performed through the invocation and execution of smart contracts.This leads to extensive combinations between blockchain,smart contract,Internet of Things(IoT)and Cyber-Physical System(CPS)applications,and then many blockchain-based IoT or CPS applications emerge to provide multiple benefits to the economy and society.In this case,obtaining a better understanding of smart contracts will contribute to the easier operation,higher efficiency and stronger security of those blockchain-based systems and applications.Many existing studies on smart contract analysis are based on similarity calculation and smart contract classification.However,smart contract is a piece of code with special characteristics and most of smart contracts are stored without any category labels,which leads to difficulties of smart contract classification.As the back end of a blockchain-based Decentralized Application(DApp)is one or several smart contracts,DApps with labeled categories and open source codes are applied to achieve a supervised smart contract classification.A three-phase approach is proposed to categorize DApps based on various data features.In this approach,5,659 DApps with smart contract source codes and pre-tagged categories are first obtained based on massive collected DApps and smart contracts from Ethereum,State of the DApps and DappRadar.Then feature extraction and construction methods are designed to form multi-feature vectors that could present the major characteristics of DApps.Finally,a fused classification model consisting of KNN,XGBoost and random forests is applied to the multi-feature vectors of all DApps for performing DApp classification.The experimental results show that the method is effective.In addition,some positive correlations between feature variables and categories,as well as several user behavior patterns of DApp calls,are found in this paper.
文摘This paper theoretically analyzes a deficiency of the existing scheme, and proposes a distributed multi-hop certification authority scheme for mobile Ad Hoc networks. In our design, we distribute the certification authority functions through a threshold secret sharing mechanism, in which each node holds a secret share and multiple nodes jointly provide complete services. Certification authority is not limited in a local neighborhood but can be completed within multi-hop location. In addition, we replace broadcast by multicast to improve system performance and reduce communication overhead. This paper resolves some technical problems of ubiquitous certification authority services, and presents a wieldy multi-hop certification authority algorithm. Simulation results confirm the availability and effectiveness of our design.
文摘Forest sustainability is the foundation of forestry and modern forest management. Originally the central concept was sustained-yield and maximum timber production and then multiple-use and other non-timber values gained importance. After the Rio Conference and development of the Montréal Process in the early 1990’s, forest sustainability rapidly gained importance and various forest certification schemes developed to certify forest products that were grown using sustainable forest management. Forest sustainability and forest certification have become critical topics in forestry curricula. The American Tree Farm System is one of the important North American forest certification organizations. Modern forestry curricula often include a capstone course where forest management plans are developed. We describe a capstone course at Clemson University under development that uses the management standards and management plan template of the American Tree Farm System as a framework for students to develop actual forest management plans for local forest owners. The material is integrated into a series of four courses leading up to the capstone course. The course offered a hands-on approach for students to create management plans using actual certification standards and the system’s management plan template. In addition, students received specialized training to qualify as auditors for the certification system. This is an example of forest sustainability being integrated into the forestry curriculum.
文摘Distributed certification via threshold cryptography is much more secu re than other ways to protect certification authority (CA) 's private key,and c an tolerate some intrusions. As the original system such as ITTC,etc.,is unsaf e ,inefficient and impracitcal in actual network environment,this paper brings u p a new distributed certification scheme,which although it generates key shares concentratively,it updates key shares distributedly,and so,avoids single-po in t failure like ITTC. It not only enhances robustness with Feldman verification and SSL protocol,but can also change the threshold (t,k) flexibly and robu stly,and so,is much more practical. In this work,the authors implement the prototype sy stem of the new scheme and test and analyze its performance.
文摘On weekends,Ms.Ran,who works in the Internet industry,goes to the Beijing Country Fair to buy vegetables,fruits and yoghourt."Before when I bought fruits at the stalls along the streets,I always asked whether the fruit is suitable for pregnant women,"said Ms.Ran.She tried to learn if the vendor would admit the fruits had much pesticide residue,
基金supported in part by the National Natural Science Foundation Project of China under Grant No.62062009the Guangxi Innovation-Driven Development Project under Grant Nos.AA17204058-17 and AA18118047-7.
文摘Smart parks serve as integral components of smart cities,where they play a pivotal role in the process of urban modernization.The demand for cross-domain cooperation among smart devices from various parks has witnessed a significant increase.To ensure secure communication,device identities must undergo authentication.The existing cross-domain authentication schemes face issues such as complex authentication paths and high certificate management costs for devices,making it impractical for resource-constrained devices.This paper proposes a blockchain-based lightweight and efficient cross-domain authentication protocol for smart parks,which simplifies the authentication interaction and requires every device to maintain only one certificate.To enhance cross-domain cooperation flexibility,a comprehensive certificate revocation mechanism is presented,significantly reducing certificate management costs while ensuring efficient and secure identity authentication.When a park needs to revoke access permissions of several cooperative partners,the revocation of numerous cross-domain certificates can be accomplished with a single blockchain write operation.The security analysis and experimental results demonstrate the security and effectiveness of our scheme.
基金Supported by the National Philosophy and Social Sciences Foundation(09XJY024)
文摘According to the investigation results of 70 green food enterprises in Sichuan Province,the strategic targets of enterprises implementing green food certification are discussed by borrowing ideas from the Balanced Score Card.Balanced Score Card index system is selected and improved according to the changes of enterprises before and after implementing the green food certification system.Then,the performance evaluation index system of enterprises implementing green food certification is established.This index system has five strategic directions of finance,customer,internal management,social ecology,and learning and growth,and has 11 strategic targets,such as increasing operating profit,expanding market,improving the quality of staff,improving the production technology level,enhancing the core competence of enterprises,ensuring food safety,improving the physical quality of human,and protecting ecological environment.According to the principles of guidance,scientificity,comparability,feasibility,and significance,a total of 24 evaluation indices are established,including the change of product cost,change of product sales revenue,change of profit rate,change of return on investment,change of internal and external lost cost,change of the proportion of certified products in total sales and so on.
文摘Since the middle 1990s, ecotourism certification has been given more and more attention to around the world.As a developing country with abundant ecotourism products, it is necessary for China to adopt certification to ensuresustainable development of ecotourism. But there are few products certificated until now in China. After reviewing thetrend of ecotourism certification in the world and summarizing its theory and method, this paper analyzes the progressand prospect of ecotourism certification in China, and concludes that certification in China is necessary and promising.
文摘We explore the organizational, environmental, and economic effects of sustainable forest management （FM） certification by Smart- Wood （SW）, one of the certification bodies accredited by the Forest Stewardship Council （FSC） to carry out certification in Japan. We closely investigated three enterprises： the Yusuhara Forest Owners＇ Cooperative, Yamanashi Prefectural Forest, and Ryujin-mura Forest Owners＇ Coopera- tive. Interviews with representatives of these entities provided crucial empirical information regarding the influence of certification on envi- ronmental assessment, rare-species protection, landscape-management planning, management objectives, and forest supervision. Attainment of FM status improved environmental awareness and engendered positive changes in assessing and managing forests and other natural resources but simultaneously imposed heavier economic costs.
