Prepared with concrete and pragmatic questions,members of a media delegation from the Republic of the Congo toured the cities of Yunfu and Zhaoqing in Guangdong Province from 16 to 22 November 2025.They visited produc...Prepared with concrete and pragmatic questions,members of a media delegation from the Republic of the Congo toured the cities of Yunfu and Zhaoqing in Guangdong Province from 16 to 22 November 2025.They visited production workshops,explored research institutes,toured beautiful villages and discovered archaeological sites,searching for the keys to Chinese modernisation in its many dimensions.展开更多
Trust management was discussed according to the security requirements in distributed environment.A graph-based delegable model and its formal description were given.Permissions propagating to control,conflict and cycl...Trust management was discussed according to the security requirements in distributed environment.A graph-based delegable model and its formal description were given.Permissions propagating to control,conflict and cyclic in delegable model were analyzed and resolved.Fi-nally,the scheme of determining access request of subject in distributed environment and future work was proposed.展开更多
The next-generation RAN,known as Open Radio Access Network(ORAN),allows for several advantages,including cost-effectiveness,network flexibility,and interoperability.Now ORAN applications,utilising machine learning(ML)...The next-generation RAN,known as Open Radio Access Network(ORAN),allows for several advantages,including cost-effectiveness,network flexibility,and interoperability.Now ORAN applications,utilising machine learning(ML)and artificial intelligence(AI)techniques,have become standard practice.The need for Federated Learning(FL)for ML model training in ORAN environments is heightened by the modularised structure of the ORAN architecture and the shortcomings of conventional ML techniques.However,the traditional plaintext model update sharing of FL in multi-BS contexts is susceptible to privacy violations such as deep-leakage gradient assaults and inference.Therefore,this research presents a novel blockchain-assisted improved cryptographic privacy-preserving federated learning(BICPPFL)model,with the help of ORAN,to safely carry out federated learning and protect privacy.This model improves on the conventional masking technique for sharing model parameters by adding new characteristics.These features include the choice of distributed aggregators,validation for final model aggregation,and individual validation for BSs.To manage the security and privacy of FL processes,a combined homomorphic proxy-reencryption(HPReE)and lattice-cryptographic method(HPReEL)has been used.The upgraded delegated proof of stake(Up-DPoS)consensus protocol,which will provide quick validation of model exchanges and protect against malicious attacks,is employed for effective consensus across blockchain nodes.Without sacrificing performance metrics,the BICPPFL model strengthens privacy and adds security layers while facilitating the transfer of sensitive data across several BSs.The framework is deployed on top of a Hyperledger Fabric blockchain to evaluate its effectiveness.The experimental findings prove the reliability and privacy-preserving capability of the BICPPFL model.展开更多
With the popularity of cloud computing and mobile Apps, on-demand services such as on-line music or audio streaming and vehicle booking are widely available nowadays. In order to allow efficient delivery and managemen...With the popularity of cloud computing and mobile Apps, on-demand services such as on-line music or audio streaming and vehicle booking are widely available nowadays. In order to allow efficient delivery and management of the services, for large-scale on-demand systems, there is usually a hierarchy where the service provider can delegate its service to a top-tier （e.g., countrywide） proxy who can then further delegate the service to lower level （e.g., region-wide） proxies. Secure （re-）delegation and revocation are among the most crucial factors for such systems. In this paper, we investigate the practical solutions for achieving re-delegation and revocation utilizing proxy signature. Although proxy signature has been extensively studied in the literature, no previous solution can achieve both properties. To fill the gap, we introduce the notion of revocable and re-delegable proxy signature that supports efficient revocation and allows a proxy signer to re-delegate its signing right to other proxy signers without the interaction with the original signer. We define the formal security models for this new primitive and present an efficient scheme that can achieve all the security properties. We also present a secure on-line revocable and re-delegate vehicle ordering system （RRVOS） as one of the applications of our proposed scheme.展开更多
In this paper,we propose the concept of delegable zero knowledge succinct non-interactive arguments of knowledge(zk-SNARKs).The delegable zk-SNARKKis parameterized by(u,k,k',k").The delegable property of zk-S...In this paper,we propose the concept of delegable zero knowledge succinct non-interactive arguments of knowledge(zk-SNARKs).The delegable zk-SNARKKis parameterized by(u,k,k',k").The delegable property of zk-SNARKs allows the prover to delegate its proving ability toμproxies.Any k honest proxies are able to generate the correct proof for a statement,but the collusion of less than k proxies does not obtain information about the witness of the statement.We also define k'-soundness and k"-zero knowledge by taking into consider of multi-proxies.We propose a construction of(μ,2t+1,t,t)-delegable zk-SNARK for the NPC language of arithmetic circuit satisfiability.Our delegable zk-SNARK stems from Groth's zk-SNARK scheme(Groth16).We take advantage of the additive and multiplicative properties of polynomial-based secret sharing schemes to achieve delegation for zk-SNARK.Our secret sharing scheme works well with the pairing groups so that the nice succinct properties of Groth's zk-SNARK scheme are preserved,while augmenting the delegable property and keeping soundness and zero-knowledge in the scenario of multi-proxies.展开更多
To solve the challenges of connecting and coordinating multiple platforms in the automotive industry and to enhance collaboration among different participants,this research focuses on addressing the complex supply rel...To solve the challenges of connecting and coordinating multiple platforms in the automotive industry and to enhance collaboration among different participants,this research focuses on addressing the complex supply relationships in the automotive market,improving data sharing and interactions across various platforms,and achieving more detailed integration of data and operations.We propose a trust evaluation permission delegation method based on the automotive industry chain.The proposed method combines smart contracts with trust evaluation mechanisms,dynamically calculating the trust value of users based on the historical behavior of the delegated entity,network environment,and other factors to avoid malicious node attacks during the permission delegation process.We also introduce strict control over the cross-domain permission granting and revocation mechanisms to manage the delegation path,prevent information leakage caused by malicious node interception,and effectively protect data integrity and privacy.Experimental analysis shows that this method meets the realtime requirements of collaborative interaction in the automotive industry chain and provides a feasible solution to permission delegation issues in the automotive industry chain,offering dynamic flexibility in authorization and scalability compared to most existing solutions.展开更多
At the invitation of the Friedrich Ebert Foundation(Friedrich-Ebert-Stiftung),the Thai-Chinese Culture and Economy Association and the Viet Nam Union of Friendship Organisations,a CAFIU delegation headed by President ...At the invitation of the Friedrich Ebert Foundation(Friedrich-Ebert-Stiftung),the Thai-Chinese Culture and Economy Association and the Viet Nam Union of Friendship Organisations,a CAFIU delegation headed by President Ji Bingxuan,also Vice-Chairperson of the Standing Committee of the 13th National People's Congress of China visited Germany,Thailand and Vietnam from 26 November to 5 December 2024.展开更多
The G20 Youth Summit(Y20)took place in Johannesburg,South Africa,from 18 to 23 August.Sun Ruoshui,a research assistant from the Institute of Climate Change and Sustainable Development,Tsinghua University,was appointed...The G20 Youth Summit(Y20)took place in Johannesburg,South Africa,from 18 to 23 August.Sun Ruoshui,a research assistant from the Institute of Climate Change and Sustainable Development,Tsinghua University,was appointed by the All-China Youth Federation to represent China in the discussions on Climate and Environmental Sustainability.Specialising in global climate governance,international climate negotiation and climate policy,Sun has previously served as a member of the Chinese delegation to the 2023 United Nations Climate Change Conference(COP28)and 2024 Bonn Subsidiary Bodies Meeting.展开更多
In a peach orchard in Lyuxiang Town,Jinshan District,Shanghai,youth delegates from 13 countries,officials from the Food and Agriculture Organization of the United Nations(FAO),and agricultural heritage experts were im...In a peach orchard in Lyuxiang Town,Jinshan District,Shanghai,youth delegates from 13 countries,officials from the Food and Agriculture Organization of the United Nations(FAO),and agricultural heritage experts were impressed by sweet and juicy Jinshan flat peaches.Jinshan has a history of flat peach cultivation that spans hundreds of years dating back to the Yuan Dynasty(1271-1368).展开更多
On 22 January 2025,the delegation of Harvard Students'China Trek 2025 arrived in Hangzhou.Forty-six students from Harvard Kennedy School,representing 20 countries,engaged in in-depth exchanges with Chinese and int...On 22 January 2025,the delegation of Harvard Students'China Trek 2025 arrived in Hangzhou.Forty-six students from Harvard Kennedy School,representing 20 countries,engaged in in-depth exchanges with Chinese and international youth delegates,embarking on a journey promoting mutual learning and strengthening friendship.展开更多
From 9 to 12 March 2025,representatives of China NGO Network for International Exchanges(CNIE)attended the 69th Session of the United Nations Commission on the Status of Women(CSW 69)in New York,USA.
From May 14 to 17,2025,at the invitation of the Hellenic Clothing Industry Association and the Greek Enterprise Bureau,Sun Ruizhe,president of the China National Textile and Apparel Council(hereinafter referred to as ...From May 14 to 17,2025,at the invitation of the Hellenic Clothing Industry Association and the Greek Enterprise Bureau,Sun Ruizhe,president of the China National Textile and Apparel Council(hereinafter referred to as CNTAC),led a team to visit Greece to carry out industrial communication and economic cooperation.This visit not only deepened the mutual trust and cooperation in the textile industry between China and Greece but also opened up new pathways for bilateral industrial connections.展开更多
At the invitation of the Madagascar-China Friendship Group of the National Assembly of Madagascar,Li Jun,former Vice-Minister of the International Department of the CPC Central Committee and Vice-President of CNIE,led...At the invitation of the Madagascar-China Friendship Group of the National Assembly of Madagascar,Li Jun,former Vice-Minister of the International Department of the CPC Central Committee and Vice-President of CNIE,led a sixmember delegation to visit Madagascar from May 11th to 14th,2025.During the delegation's visit,Justin Tokely,Speaker of the National Assembly of Madagascar and Razafinarivo Augustin,Deputy Speaker met with the delegation.The delegation exchanged views with Rafidi,Director of the Madagascar Economic Development Bureau as well as leaders of local NGOs on Belt and Road cooperation and peopleto-people exchanges.展开更多
传统的MVC模式在表示层和业务逻辑层存在大量的数据交换,降低了系统的效率,讨论了在软件开发过程中具体存在的问题,分析了Session Fa ade和Business Delegate两种设计模式的特点,提出将这2种模式和MVC模式结合,形成完善的J2EE开发模式....传统的MVC模式在表示层和业务逻辑层存在大量的数据交换,降低了系统的效率,讨论了在软件开发过程中具体存在的问题,分析了Session Fa ade和Business Delegate两种设计模式的特点,提出将这2种模式和MVC模式结合,形成完善的J2EE开发模式.同时,对J2EE架构中的数据持久层进行分析和改进,提出用DAO类和DAO-Factory类实现数据持久层的方法,形成更完善的J2EE体系结构.展开更多
文摘Prepared with concrete and pragmatic questions,members of a media delegation from the Republic of the Congo toured the cities of Yunfu and Zhaoqing in Guangdong Province from 16 to 22 November 2025.They visited production workshops,explored research institutes,toured beautiful villages and discovered archaeological sites,searching for the keys to Chinese modernisation in its many dimensions.
文摘Trust management was discussed according to the security requirements in distributed environment.A graph-based delegable model and its formal description were given.Permissions propagating to control,conflict and cyclic in delegable model were analyzed and resolved.Fi-nally,the scheme of determining access request of subject in distributed environment and future work was proposed.
文摘The next-generation RAN,known as Open Radio Access Network(ORAN),allows for several advantages,including cost-effectiveness,network flexibility,and interoperability.Now ORAN applications,utilising machine learning(ML)and artificial intelligence(AI)techniques,have become standard practice.The need for Federated Learning(FL)for ML model training in ORAN environments is heightened by the modularised structure of the ORAN architecture and the shortcomings of conventional ML techniques.However,the traditional plaintext model update sharing of FL in multi-BS contexts is susceptible to privacy violations such as deep-leakage gradient assaults and inference.Therefore,this research presents a novel blockchain-assisted improved cryptographic privacy-preserving federated learning(BICPPFL)model,with the help of ORAN,to safely carry out federated learning and protect privacy.This model improves on the conventional masking technique for sharing model parameters by adding new characteristics.These features include the choice of distributed aggregators,validation for final model aggregation,and individual validation for BSs.To manage the security and privacy of FL processes,a combined homomorphic proxy-reencryption(HPReE)and lattice-cryptographic method(HPReEL)has been used.The upgraded delegated proof of stake(Up-DPoS)consensus protocol,which will provide quick validation of model exchanges and protect against malicious attacks,is employed for effective consensus across blockchain nodes.Without sacrificing performance metrics,the BICPPFL model strengthens privacy and adds security layers while facilitating the transfer of sensitive data across several BSs.The framework is deployed on top of a Hyperledger Fabric blockchain to evaluate its effectiveness.The experimental findings prove the reliability and privacy-preserving capability of the BICPPFL model.
文摘With the popularity of cloud computing and mobile Apps, on-demand services such as on-line music or audio streaming and vehicle booking are widely available nowadays. In order to allow efficient delivery and management of the services, for large-scale on-demand systems, there is usually a hierarchy where the service provider can delegate its service to a top-tier （e.g., countrywide） proxy who can then further delegate the service to lower level （e.g., region-wide） proxies. Secure （re-）delegation and revocation are among the most crucial factors for such systems. In this paper, we investigate the practical solutions for achieving re-delegation and revocation utilizing proxy signature. Although proxy signature has been extensively studied in the literature, no previous solution can achieve both properties. To fill the gap, we introduce the notion of revocable and re-delegable proxy signature that supports efficient revocation and allows a proxy signer to re-delegate its signing right to other proxy signers without the interaction with the original signer. We define the formal security models for this new primitive and present an efficient scheme that can achieve all the security properties. We also present a secure on-line revocable and re-delegate vehicle ordering system （RRVOS） as one of the applications of our proposed scheme.
基金Shengli Liu and Jinrui Sha were partially sponsored by the National Key R&D Program of China(No.2022YFB2701503)the National Natural Science Foundation of China(Grant No.61925207)Guangdong Major Project of Basic and Applied Basic Research(No.2019B030302008).
文摘In this paper,we propose the concept of delegable zero knowledge succinct non-interactive arguments of knowledge(zk-SNARKs).The delegable zk-SNARKKis parameterized by(u,k,k',k").The delegable property of zk-SNARKs allows the prover to delegate its proving ability toμproxies.Any k honest proxies are able to generate the correct proof for a statement,but the collusion of less than k proxies does not obtain information about the witness of the statement.We also define k'-soundness and k"-zero knowledge by taking into consider of multi-proxies.We propose a construction of(μ,2t+1,t,t)-delegable zk-SNARK for the NPC language of arithmetic circuit satisfiability.Our delegable zk-SNARK stems from Groth's zk-SNARK scheme(Groth16).We take advantage of the additive and multiplicative properties of polynomial-based secret sharing schemes to achieve delegation for zk-SNARK.Our secret sharing scheme works well with the pairing groups so that the nice succinct properties of Groth's zk-SNARK scheme are preserved,while augmenting the delegable property and keeping soundness and zero-knowledge in the scenario of multi-proxies.
基金funded by the Sichuan Science and Technology Program,Grant Nos.2024NSFSC0515,2024ZHCG0182 and MZGC20230013.
文摘To solve the challenges of connecting and coordinating multiple platforms in the automotive industry and to enhance collaboration among different participants,this research focuses on addressing the complex supply relationships in the automotive market,improving data sharing and interactions across various platforms,and achieving more detailed integration of data and operations.We propose a trust evaluation permission delegation method based on the automotive industry chain.The proposed method combines smart contracts with trust evaluation mechanisms,dynamically calculating the trust value of users based on the historical behavior of the delegated entity,network environment,and other factors to avoid malicious node attacks during the permission delegation process.We also introduce strict control over the cross-domain permission granting and revocation mechanisms to manage the delegation path,prevent information leakage caused by malicious node interception,and effectively protect data integrity and privacy.Experimental analysis shows that this method meets the realtime requirements of collaborative interaction in the automotive industry chain and provides a feasible solution to permission delegation issues in the automotive industry chain,offering dynamic flexibility in authorization and scalability compared to most existing solutions.
文摘At the invitation of the Friedrich Ebert Foundation(Friedrich-Ebert-Stiftung),the Thai-Chinese Culture and Economy Association and the Viet Nam Union of Friendship Organisations,a CAFIU delegation headed by President Ji Bingxuan,also Vice-Chairperson of the Standing Committee of the 13th National People's Congress of China visited Germany,Thailand and Vietnam from 26 November to 5 December 2024.
文摘The G20 Youth Summit(Y20)took place in Johannesburg,South Africa,from 18 to 23 August.Sun Ruoshui,a research assistant from the Institute of Climate Change and Sustainable Development,Tsinghua University,was appointed by the All-China Youth Federation to represent China in the discussions on Climate and Environmental Sustainability.Specialising in global climate governance,international climate negotiation and climate policy,Sun has previously served as a member of the Chinese delegation to the 2023 United Nations Climate Change Conference(COP28)and 2024 Bonn Subsidiary Bodies Meeting.
文摘In a peach orchard in Lyuxiang Town,Jinshan District,Shanghai,youth delegates from 13 countries,officials from the Food and Agriculture Organization of the United Nations(FAO),and agricultural heritage experts were impressed by sweet and juicy Jinshan flat peaches.Jinshan has a history of flat peach cultivation that spans hundreds of years dating back to the Yuan Dynasty(1271-1368).
文摘On 22 January 2025,the delegation of Harvard Students'China Trek 2025 arrived in Hangzhou.Forty-six students from Harvard Kennedy School,representing 20 countries,engaged in in-depth exchanges with Chinese and international youth delegates,embarking on a journey promoting mutual learning and strengthening friendship.
文摘From 9 to 12 March 2025,representatives of China NGO Network for International Exchanges(CNIE)attended the 69th Session of the United Nations Commission on the Status of Women(CSW 69)in New York,USA.
文摘From May 14 to 17,2025,at the invitation of the Hellenic Clothing Industry Association and the Greek Enterprise Bureau,Sun Ruizhe,president of the China National Textile and Apparel Council(hereinafter referred to as CNTAC),led a team to visit Greece to carry out industrial communication and economic cooperation.This visit not only deepened the mutual trust and cooperation in the textile industry between China and Greece but also opened up new pathways for bilateral industrial connections.
文摘At the invitation of the Madagascar-China Friendship Group of the National Assembly of Madagascar,Li Jun,former Vice-Minister of the International Department of the CPC Central Committee and Vice-President of CNIE,led a sixmember delegation to visit Madagascar from May 11th to 14th,2025.During the delegation's visit,Justin Tokely,Speaker of the National Assembly of Madagascar and Razafinarivo Augustin,Deputy Speaker met with the delegation.The delegation exchanged views with Rafidi,Director of the Madagascar Economic Development Bureau as well as leaders of local NGOs on Belt and Road cooperation and peopleto-people exchanges.
文摘传统的MVC模式在表示层和业务逻辑层存在大量的数据交换,降低了系统的效率,讨论了在软件开发过程中具体存在的问题,分析了Session Fa ade和Business Delegate两种设计模式的特点,提出将这2种模式和MVC模式结合,形成完善的J2EE开发模式.同时,对J2EE架构中的数据持久层进行分析和改进,提出用DAO类和DAO-Factory类实现数据持久层的方法,形成更完善的J2EE体系结构.
