To verify the effectiveness and correctness of the protection settings in ring structure Shipboard Power System (SPS), a digital-physical hybrid simulation platform at China Ship Development and Design Center (CSDDC) ...To verify the effectiveness and correctness of the protection settings in ring structure Shipboard Power System (SPS), a digital-physical hybrid simulation platform at China Ship Development and Design Center (CSDDC) has been built, which aims to give double verification effect of design scheme and physical device. The platform consists of eMEGAsim digital simulator, signal power amplifiers and digital-analog interface equipments. With this platform, the multiple protection device of ring structure grid can be accessed to form a close-loop test system. Since eMEGAsim model-simulated faults and actual protection device actions are on real time, the tripping settings of each device as well as their coordinate performance between multiple devices can be verified in this close-loop test.展开更多
The concept of batch verifying multiple digital signatures is to find a method by which multiple digital signatures can be verified simultaneously in a lower time complexity than separately verifying all the signature...The concept of batch verifying multiple digital signatures is to find a method by which multiple digital signatures can be verified simultaneously in a lower time complexity than separately verifying all the signatures. In this article, we analyze the complexity of the batch verifying schemes defined by Li, Hwang and Chen in 2010, and propose a new batch verifying multiple digital signature scheme, in two variants： one for RSA - by completing the Harn＇s schema with an identifying illegal signatures algorithm, and the other adapted for a modified Elliptic Curve Digital Siggnature Algorithm protocol.展开更多
Challenges and focus that Measureable, Reportable and Verifiable of REDD+ activities will face are analyzed base on provisions relate to MRV for REDD+ in UNFCCC.It will face the challenges of lake of messages in estim...Challenges and focus that Measureable, Reportable and Verifiable of REDD+ activities will face are analyzed base on provisions relate to MRV for REDD+ in UNFCCC.It will face the challenges of lake of messages in estimating biomass carbon storage and reference level,certification standards, the national methodology of REDD+ activities,and financial support if measurable,reportable and verifiable REDD+ activities are developed in China. Based on the results of the analysis,the different types for REDD+ activities that adapt to Chinese situation are put forward,and it was designed that the framework on Measuring,Reporting and Verifying System for REDD+ activities in China including general indicator such as objectives, implementation,contribution to sustainable development and poverty eradication,environment effectiveness,sustainability and cost-effectiveness.展开更多
Dear Editor,We present a modified surgical technique to verify the chorion layer of the human amniotic membrane(hAM)in treating retinal detachment(RD)with vitrectomy.RD patients with pathological myopia where the tear...Dear Editor,We present a modified surgical technique to verify the chorion layer of the human amniotic membrane(hAM)in treating retinal detachment(RD)with vitrectomy.RD patients with pathological myopia where the tear is located within the posterior pole choroidal atrophy area are difficult to treat.Surgical procedures such as laser treatments,diathermy,cryopexy applications or long-term silicone oil endotamponade may not only be ineffective but also harmful in these cases^([1]).Amniotic membrane transplantation(AMT)is an effective technique in case of RD recurrences to seal retinal holes over high myopic chorioretinal atrophy^([2]).展开更多
Theproliferation of Internet of Things(IoT)devices introduces substantial security challenges.Currently,privacy constitutes a significant concern for individuals.While maintaining privacy within these systems is an es...Theproliferation of Internet of Things(IoT)devices introduces substantial security challenges.Currently,privacy constitutes a significant concern for individuals.While maintaining privacy within these systems is an essential characteristic,it often necessitates certain compromises,such as complexity and scalability,thereby complicating management efforts.The principal challenge lies in ensuring confidentiality while simultaneously preserving individuals’anonymity within the system.To address this,we present our proposed architecture for managing IoT devices using blockchain technology.Our proposed architecture works on and off blockchain and is integrated with dashcams and closed-circuit television(CCTV)security cameras.In this work,the videos recorded by the dashcams and CCTV security cameras are hashed through the InterPlanetary File System(IPFS)and this hash is stored in the blockchain.When the accessors want to access the video,they must pass through multiple authentications which include web token authentication and verifiable credentials,to mitigate the risk of malicious users.Our contributions include the proposition of the framework,which works on the single key for every new video,and a novel chaincode algorithm that incorporates verifiable credentials.Analyses are made to show the system’s throughput and latency through stress testing.Significant advantages of the proposed architecture are shown by comparing them to existing schemes.The proposed architecture features a robust design that significantly enhances the security of blockchain-enabled Internet of Things(IoT)deviceswhile effectively mitigating the risk of a single point of failure,which provides a reliable solution for security concerns in the IoT landscape.Our future endeavors will focus on scaling the system by integrating innovative methods to enhance security measures further.展开更多
The wide application of smart contracts allows industry companies to implement some complex distributed collaborative businesses,which involve the calculation of complex functions,such as matrix operations.However,com...The wide application of smart contracts allows industry companies to implement some complex distributed collaborative businesses,which involve the calculation of complex functions,such as matrix operations.However,complex functions such as matrix operations are difficult to implement on Ethereum Virtual Machine(EVM)-based smart contract platforms due to their distributed security environment limitations.Existing off-chain methods often result in a significant reduction in contract execution efficiency,thus a platform software development kit interface implementation method has become a feasible way to reduce overheads,but this method cannot verify operation correctness and may leak sensitive user data.To solve the above problems,we propose a verifiable EVM-based smart contract cross-language implementation scheme for complex operations,especially matrix operations,which can guarantee operation correctness and user privacy while ensuring computational efficiency.In this scheme,a verifiable interaction process is designed to verify the computation process and results,and a matrix blinding technology is introduced to protect sensitive user data in the calculation process.The security analysis and performance tests show that the proposed scheme can satisfy the correctness and privacy of the cross-language implementation of smart contracts at a small additional efficiency cost.展开更多
Distributed data fusion is essential for numerous applications,yet faces significant privacy security challenges.Federated learning(FL),as a distributed machine learning paradigm,offers enhanced data privacy protectio...Distributed data fusion is essential for numerous applications,yet faces significant privacy security challenges.Federated learning(FL),as a distributed machine learning paradigm,offers enhanced data privacy protection and has attracted widespread attention.Consequently,research increasingly focuses on developing more secure FL techniques.However,in real-world scenarios involving malicious entities,the accuracy of FL results is often compromised,particularly due to the threat of collusion between two servers.To address this challenge,this paper proposes an efficient and verifiable data aggregation protocol with enhanced privacy protection.After analyzing attack methods against prior schemes,we implement key improvements.Specifically,by incorporating cascaded random numbers and perturbation terms into gradients,we strengthen the privacy protection afforded by polynomial masking,effectively preventing information leakage.Furthermore,our protocol features an enhanced verification mechanism capable of detecting collusive behaviors between two servers.Accuracy testing on the MNIST and CIFAR-10 datasets demonstrates that our protocol maintains accuracy comparable to the Federated Averaging Algorithm.In scheme efficiency comparisons,while incurring only a marginal increase in verification overhead relative to the baseline scheme,our protocol achieves an average improvement of 93.13% in privacy protection and verification overhead compared to the state-of-the-art scheme.This result highlights its optimal balance between overall overhead and functionality.A current limitation is that the verificationmechanismcannot precisely pinpoint the source of anomalies within aggregated results when server-side malicious behavior occurs.Addressing this limitation will be a focus of future research.展开更多
Ciphertext-Policy Attribute-Based Encryption(CP-ABE)enables fine-grained access control on ciphertexts,making it a promising approach for managing data stored in the cloud-enabled Internet of Things.But existing schem...Ciphertext-Policy Attribute-Based Encryption(CP-ABE)enables fine-grained access control on ciphertexts,making it a promising approach for managing data stored in the cloud-enabled Internet of Things.But existing schemes often suffer from privacy breaches due to explicit attachment of access policies or partial hiding of critical attribute content.Additionally,resource-constrained IoT devices,especially those adopting wireless communication,frequently encounter affordability issues regarding decryption costs.In this paper,we propose an efficient and fine-grained access control scheme with fully hidden policies(named FHAC).FHAC conceals all attributes in the policy and utilizes bloom filters to efficiently locate them.A test phase before decryption is applied to assist authorized users in finding matches between their attributes and the access policy.Dictionary attacks are thwarted by providing unauthorized users with invalid values.The heavy computational overhead of both the test phase and most of the decryption phase is outsourced to two cloud servers.Additionally,users can verify the correctness of multiple outsourced decryption results simultaneously.Security analysis and performance comparisons demonstrate FHAC's effectiveness in protecting policy privacy and achieving efficient decryption.展开更多
This paper presents 3RVAV(Three-Round Voting with Advanced Validation),a novel Byzantine Fault Tolerant consensus protocol combining Proof-of-Stake with a multi-phase voting mechanism.The protocol introduces three lay...This paper presents 3RVAV(Three-Round Voting with Advanced Validation),a novel Byzantine Fault Tolerant consensus protocol combining Proof-of-Stake with a multi-phase voting mechanism.The protocol introduces three layers of randomized committee voting with distinct participant roles(Validators,Delegators,and Users),achieving(4/5)-threshold approval per round through a verifiable random function(VRF)-based selection process.Our security analysis demonstrates 3RVAV provides 1−(1−s/n)^(3k) resistance to Sybil attacks with n participants and stake s,while maintaining O(kn log n)communication complexity.Experimental simulations show 3247 TPS throughput with 4-s finality,representing a 5.8×improvement over Algorand’s committee-based approach.The proposed protocol achieves approximately 4.2-s finality,demonstrating low latency while maintaining strong consistency and resilience.The protocol introduces a novel punishment matrix incorporating both stake slashing and probabilistic blacklisting,proving a Nash equilibrium for honest participation under rational actor assumptions.展开更多
Federated Learning(FL)has emerged as a promising distributed machine learning paradigm that enables multi-party collaborative training while eliminating the need for raw data sharing.However,its reliance on a server i...Federated Learning(FL)has emerged as a promising distributed machine learning paradigm that enables multi-party collaborative training while eliminating the need for raw data sharing.However,its reliance on a server introduces critical security vulnerabilities:malicious servers can infer private information from received local model updates or deliberately manipulate aggregation results.Consequently,achieving verifiable aggregation without compromising client privacy remains a critical challenge.To address these problem,we propose a reversible data hiding in encrypted domains(RDHED)scheme,which designs joint secret message embedding and extraction mechanism.This approach enables clients to embed secret messages into ciphertext redundancy spaces generated during model encryption.During the server aggregation process,the embedded messages from all clients fuse within the ciphertext space to form a joint embedding message.Subsequently,clients can decrypt the aggregated results and extract this joint embedding message for verification purposes.Building upon this foundation,we integrate the proposed RDHED scheme with linear homomorphic hash and digital signatures to design a verifiable privacy-preserving aggregation protocol for single-server architectures(VPAFL).Theoretical proofs and experimental analyses show that VPAFL can effectively protect user privacy,achieve lightweight computational and communication overhead of users for verification,and present significant advantages with increasing model dimension.展开更多
To enable efficient sharing of unbounded streaming data,this paper introduces blockchain technology into traditional cloud data,proposing a hybrid on-chain/off-chain storage model.We design a real-time verifiable data...To enable efficient sharing of unbounded streaming data,this paper introduces blockchain technology into traditional cloud data,proposing a hybrid on-chain/off-chain storage model.We design a real-time verifiable data structure that is more suitable for streaming data to achieve efficient real-time verifiability for streaming data.Based on the notch gate hash function and vector commitment,an adaptive notch gate hash tree structure is constructed,and an efficient real-time verifiable data structure for on-chain and off-chain stream data is proposed.The structure binds dynamic root nodes sequentially to ordered leaf nodes in its child nodes.Only the vector commitment of the dynamic root node is stored on the chain,and the complete data structure is stored off-chain.This structure ensures tamperproofing against malicious off-chain cloud servers of off-chain cloud servers.Preserves storage scalability space,realizes the immediate verification of stream data upon arrival,and the computational overhead of on-chain and off-chain hybrid storage verification is only related to the current data volume,which is more practical when dealing with stream data with unpredictable data volume.We formalize this as an efficient real-time verification scheme for stream data in on-chain and off-chain hybrid storage.Finally,the technology’s security and performance were empirically validated through rigorous analysis.展开更多
To prevent server compromise attack and password guessing attacks,an improved and efficient verifier-based key exchange protocol for three-party is proposed,which enables two clients to agree on a common session key w...To prevent server compromise attack and password guessing attacks,an improved and efficient verifier-based key exchange protocol for three-party is proposed,which enables two clients to agree on a common session key with the help of the server.In this protocol,the client stores a plaintext version of the password,while the server stores a verifier for the password.And the protocol uses verifiers to authenticate between clients and the server.The security analysis and performance comparison of the proposed protocol shows that the protocol can resist many familiar attacks including password guessing attacks,server compromise attacks,man-in-the-middle attacks and Denning-Sacco attacks,and it is more efficient.展开更多
According to the chloride corrosion environment,service life prediction model of concrete structure of sea-crossing bridge was built using modified Fick's second law and the whole probability calculation method,wh...According to the chloride corrosion environment,service life prediction model of concrete structure of sea-crossing bridge was built using modified Fick's second law and the whole probability calculation method,which was suitable for China. Furthermore,a visual service life prediction program of concrete structure was developed by optimized Monte Carlo method. Meanwhile,Life 365 program was compared,indicating reliability of the prediction program. Finally,the validity of prediction model was verified in JinTang Bridge of Zhoushan Island Mainland Linkage Project.展开更多
The primary bottleneck to extracting wood defects during ultrasonic testing is the accuracy of identifying the wood defects. The wavelet energy moment was used to extract defect features of artificial wood holes drill...The primary bottleneck to extracting wood defects during ultrasonic testing is the accuracy of identifying the wood defects. The wavelet energy moment was used to extract defect features of artificial wood holes drilled into 120 elm samples that differed in the number of holes to verify the validity of the method. Wavelet energy moment can reflect the distribution of energy along the time axis and the amount of energy in each frequency band,which can effectively extract the energy distribution characteristics of signals in each frequency band; therefore,wavelet energy moment can replace the wavelet frequency band energy and constitute wood defect feature vectors. A principal component analysis was used to normalize and reduce the dimension of the feature vectors. A total of 16 principal component features were then obtained, which can effectively extract the defect features of the different number of holes in the elm samples.展开更多
We present a new hybrid numerical scheme for two-dimensional(2D)ideal magnetohydrodynamic(MHD)equations.A simple conservation element and solution element(CESE)method is used to calculate the flow variables,and the un...We present a new hybrid numerical scheme for two-dimensional(2D)ideal magnetohydrodynamic(MHD)equations.A simple conservation element and solution element(CESE)method is used to calculate the flow variables,and the unknown first-order spatial derivatives involved in the CESE method are computed with a finite volume scheme that uses the solution of the derivative Riemann problem with limited reconstruction to evaluate the numerical flux at cell interface position.To show the validation and capacity of its application to 2D MHD problems,we study several benchmark problems.Numerical results verify that the hybrid scheme not only performs well,but also can retain the solution quality even if the Courant number ranges from close to 1 to less than 0.01.展开更多
We investigate the synchronization and anti-synchronization of the new 4D chaotic system and propose a same adaptive controller in the form which not only synchronizes,but also anti-synchronizes two identical new 4D c...We investigate the synchronization and anti-synchronization of the new 4D chaotic system and propose a same adaptive controller in the form which not only synchronizes,but also anti-synchronizes two identical new 4D chaotic systems.Numerical simulations verify the correctness and the effectiveness of the proposed theoretical results.展开更多
Digital holographic microscopy has been a powerful metrological technique for phase-contrast imaging.However inherent phase aberrations always exist and degrade the quality of the phase-contrast images.A surface fitti...Digital holographic microscopy has been a powerful metrological technique for phase-contrast imaging.However inherent phase aberrations always exist and degrade the quality of the phase-contrast images.A surface fitting method based on an improved mathematic model is proposed,which can be used to remove the phase aberrations without any pre-knowledge of the setup or manual operation.The improved mathematic model includes not only the usual terms but also the cross terms and the high order terms to describe the phase aberrations with high accuracy.Meanwhile,a non-iterative algorithm is used to solve the parametersand thus less computational load is imposed.The proposed method is applied to the live imaging of cells.The experimental results verify its validity.展开更多
This study describes an automatic berthing system with mooring lines. It is designed to be berthed by using mooring device on the upper deck of a ship. It is to berth once maintaining parallel with the quay by control...This study describes an automatic berthing system with mooring lines. It is designed to be berthed by using mooring device on the upper deck of a ship. It is to berth once maintaining parallel with the quay by controlling both forward and aft breast lines. Berthing method is used through length adjustment of mooring lines connected between ship and quay by controlling the angular velocity and the torque of hydraulic motor in mooring device. The study is conducted under three changing conditions of draft, such as even-keel, rise of the gravity center and trim to stern. Variables affecting berthing stability are determined based on the control performance of each condition. Bond graphs method is used to model the system. Controller is designed as PID control method of reference-model algorithm. The control program is composed of synchronous control system based on the equations derived with the numerical analysis. The tank test is conducted to verify the usefulness of the control program.展开更多
BACKGROUND Peripherally inserted central catheters(PICCs)are commonly used in hospitalized patients with liver cancer for the administration of chemotherapy,nutrition,and other medications.However,PICC-related thrombo...BACKGROUND Peripherally inserted central catheters(PICCs)are commonly used in hospitalized patients with liver cancer for the administration of chemotherapy,nutrition,and other medications.However,PICC-related thrombosis is a serious complication that can lead to morbidity and mortality in this patient population.Several risk factors have been identified for the development of PICC-related thrombosis,including cancer type,stage,comorbidities,and catheter characteristics.Understanding these risk factors and developing a predictive model can help healthcare providers identify high-risk patients and implement preventive measures to reduce the incidence of thrombosis.AIM To analyze the influencing factors of PICC-related thrombosis in hospitalized patients with liver cancer,construct a predictive model,and validate it.METHODS Clinical data of hospitalized patients with liver cancer admitted from January 2020 to December 2023 were collected.Thirty-five cases of PICC-related thrombosis in hospitalized patients with liver cancer were collected,and 220 patients who underwent PICC placement during the same period but did not develop PICC-related thrombosis were randomly selected as controls.A total of 255 samples were collected and used as the training set,and 77 cases were collected as the validation set in a 7:3 ratio.General patient information,case data,catheterization data,coagulation indicators,and Autar Thrombosis Risk Assessment Scale scores were analyzed.Univariate and multivariate unconditional logistic regression analyses were performed on relevant factors,and the value of combined indicators in predicting PICC-related thrombosis in hospitalized patients with liver cancer was evaluated using receiver operating characteristic(ROC)curve analysis.RESULTS Univariate analysis showed statistically significant differences(P<0.05)in age,sex,Karnofsky performance status score(KPS),bedridden time,activities of daily living impairment,parenteral nutrition,catheter duration,distant metastasis,and bone marrow suppression between the thrombosis group and the non-thrombosis group.Other aspects had no statistically significant differences(P>0.05).Multivariate regression analysis showed that age≥60 years,KPS score≤50 points,parenteral nutrition,stage III to IV,distant metastasis,bone marrow suppression,and activities of daily living impairment were independent risk factors for PICC-related thrombosis in hospitalized patients with liver cancer(P<0.05).Catheter duration of 1-6 months and catheter duration>6 months were protective factors for PICC-related thrombosis(P<0.05).The predictive model for PICC-related thrombosis was obtained as follows:P predictive probability=[exp(Logit P)]/[1+exp(Logit P)],where Logit P=age×1.907+KPS score×2.045+parenteral nutrition×9.467+catheter duration×0.506+tumor-node-metastasis(TNM)staging×2.844+distant metastasis×2.065+bone marrow suppression×2.082+activities of daily living impairment×13.926.ROC curve analysis showed an area under the curve(AUC)of 0.827(95%CI:0.724-0.929,P<0.001),with a corresponding optimal cut-off value of 0.612,sensitivity of 0.755,and specificity of 0.857.Calibration curve analysis showed good consistency between the predicted occurrence of PICC-related thrombosis and actual occurrence(P>0.05).ROC analysis showed AUCs of 0.888 and 0.729 for the training and validation sets,respectively.CONCLUSION Age,KPS score,parenteral nutrition,TNM staging,distant metastasis,bone marrow suppression,and activities of daily living impairment are independent risk factors for PICC-related thrombosis in hospitalized patients with liver cancer,while catheter duration is a protective factor for the disease.The predictive model has an AUC of 0.827,indicating high predictive accuracy and clinical value.展开更多
文摘To verify the effectiveness and correctness of the protection settings in ring structure Shipboard Power System (SPS), a digital-physical hybrid simulation platform at China Ship Development and Design Center (CSDDC) has been built, which aims to give double verification effect of design scheme and physical device. The platform consists of eMEGAsim digital simulator, signal power amplifiers and digital-analog interface equipments. With this platform, the multiple protection device of ring structure grid can be accessed to form a close-loop test system. Since eMEGAsim model-simulated faults and actual protection device actions are on real time, the tripping settings of each device as well as their coordinate performance between multiple devices can be verified in this close-loop test.
文摘The concept of batch verifying multiple digital signatures is to find a method by which multiple digital signatures can be verified simultaneously in a lower time complexity than separately verifying all the signatures. In this article, we analyze the complexity of the batch verifying schemes defined by Li, Hwang and Chen in 2010, and propose a new batch verifying multiple digital signature scheme, in two variants： one for RSA - by completing the Harn＇s schema with an identifying illegal signatures algorithm, and the other adapted for a modified Elliptic Curve Digital Siggnature Algorithm protocol.
文摘Challenges and focus that Measureable, Reportable and Verifiable of REDD+ activities will face are analyzed base on provisions relate to MRV for REDD+ in UNFCCC.It will face the challenges of lake of messages in estimating biomass carbon storage and reference level,certification standards, the national methodology of REDD+ activities,and financial support if measurable,reportable and verifiable REDD+ activities are developed in China. Based on the results of the analysis,the different types for REDD+ activities that adapt to Chinese situation are put forward,and it was designed that the framework on Measuring,Reporting and Verifying System for REDD+ activities in China including general indicator such as objectives, implementation,contribution to sustainable development and poverty eradication,environment effectiveness,sustainability and cost-effectiveness.
文摘Dear Editor,We present a modified surgical technique to verify the chorion layer of the human amniotic membrane(hAM)in treating retinal detachment(RD)with vitrectomy.RD patients with pathological myopia where the tear is located within the posterior pole choroidal atrophy area are difficult to treat.Surgical procedures such as laser treatments,diathermy,cryopexy applications or long-term silicone oil endotamponade may not only be ineffective but also harmful in these cases^([1]).Amniotic membrane transplantation(AMT)is an effective technique in case of RD recurrences to seal retinal holes over high myopic chorioretinal atrophy^([2]).
基金supported by the Institute of Information&Communications Technology Planning&Evaluation(IITP)(Project Nos.RS-2024-00438551,30%,2022-11220701,30%,2021-0-01816,30%)the National Research Foundation of Korea(NRF)grant funded by the Korean Government(Project No.RS-2023-00208460,10%).
文摘Theproliferation of Internet of Things(IoT)devices introduces substantial security challenges.Currently,privacy constitutes a significant concern for individuals.While maintaining privacy within these systems is an essential characteristic,it often necessitates certain compromises,such as complexity and scalability,thereby complicating management efforts.The principal challenge lies in ensuring confidentiality while simultaneously preserving individuals’anonymity within the system.To address this,we present our proposed architecture for managing IoT devices using blockchain technology.Our proposed architecture works on and off blockchain and is integrated with dashcams and closed-circuit television(CCTV)security cameras.In this work,the videos recorded by the dashcams and CCTV security cameras are hashed through the InterPlanetary File System(IPFS)and this hash is stored in the blockchain.When the accessors want to access the video,they must pass through multiple authentications which include web token authentication and verifiable credentials,to mitigate the risk of malicious users.Our contributions include the proposition of the framework,which works on the single key for every new video,and a novel chaincode algorithm that incorporates verifiable credentials.Analyses are made to show the system’s throughput and latency through stress testing.Significant advantages of the proposed architecture are shown by comparing them to existing schemes.The proposed architecture features a robust design that significantly enhances the security of blockchain-enabled Internet of Things(IoT)deviceswhile effectively mitigating the risk of a single point of failure,which provides a reliable solution for security concerns in the IoT landscape.Our future endeavors will focus on scaling the system by integrating innovative methods to enhance security measures further.
基金supported in part by the National Natural Science Foundation of China under Grant 62272007,U23B2002in part by the Excellent Young Talents Project of the Beijing Municipal University Teacher Team Construction Support Plan under Grant BPHR202203031+1 种基金in part by the Yunnan Key Laboratory of Blockchain Application Technology under Grant 2021105AG070005(YNB202102)in part by the Open Topics of Key Laboratory of Blockchain Technology and Data Security,The Ministry of Industry and Information Technology of the People’s Republic of China under Grant 20243222。
文摘The wide application of smart contracts allows industry companies to implement some complex distributed collaborative businesses,which involve the calculation of complex functions,such as matrix operations.However,complex functions such as matrix operations are difficult to implement on Ethereum Virtual Machine(EVM)-based smart contract platforms due to their distributed security environment limitations.Existing off-chain methods often result in a significant reduction in contract execution efficiency,thus a platform software development kit interface implementation method has become a feasible way to reduce overheads,but this method cannot verify operation correctness and may leak sensitive user data.To solve the above problems,we propose a verifiable EVM-based smart contract cross-language implementation scheme for complex operations,especially matrix operations,which can guarantee operation correctness and user privacy while ensuring computational efficiency.In this scheme,a verifiable interaction process is designed to verify the computation process and results,and a matrix blinding technology is introduced to protect sensitive user data in the calculation process.The security analysis and performance tests show that the proposed scheme can satisfy the correctness and privacy of the cross-language implementation of smart contracts at a small additional efficiency cost.
基金supported by National Key R&D Program of China(2023YFB3106100)National Natural Science Foundation of China(62102452,62172436)Natural Science Foundation of Shaanxi Province(2023-JCYB-584).
文摘Distributed data fusion is essential for numerous applications,yet faces significant privacy security challenges.Federated learning(FL),as a distributed machine learning paradigm,offers enhanced data privacy protection and has attracted widespread attention.Consequently,research increasingly focuses on developing more secure FL techniques.However,in real-world scenarios involving malicious entities,the accuracy of FL results is often compromised,particularly due to the threat of collusion between two servers.To address this challenge,this paper proposes an efficient and verifiable data aggregation protocol with enhanced privacy protection.After analyzing attack methods against prior schemes,we implement key improvements.Specifically,by incorporating cascaded random numbers and perturbation terms into gradients,we strengthen the privacy protection afforded by polynomial masking,effectively preventing information leakage.Furthermore,our protocol features an enhanced verification mechanism capable of detecting collusive behaviors between two servers.Accuracy testing on the MNIST and CIFAR-10 datasets demonstrates that our protocol maintains accuracy comparable to the Federated Averaging Algorithm.In scheme efficiency comparisons,while incurring only a marginal increase in verification overhead relative to the baseline scheme,our protocol achieves an average improvement of 93.13% in privacy protection and verification overhead compared to the state-of-the-art scheme.This result highlights its optimal balance between overall overhead and functionality.A current limitation is that the verificationmechanismcannot precisely pinpoint the source of anomalies within aggregated results when server-side malicious behavior occurs.Addressing this limitation will be a focus of future research.
基金supported in part by the National Key R&D Program of China(Grant No.2019YFB2101700)the National Natural Science Foundation of China(Grant No.62272102,No.62172320,No.U21A20466)+4 种基金the Open Research Fund of Key Laboratory of Cryptography of Zhejiang Province(Grant No.ZCL21015)the Qinghai Key R&D and Transformation Projects(Grant No.2021-GX-112)the Natural Science Foundation of Nanjing University of Posts and Telecommunications(Grant No.NY222141)the Natural Science Foundation of Jiangsu Higher Education Institutions of China under Grant(No.22KJB520029)Henan Key Laboratory of Network Cryptography Technology(No.LNCT2022-A10)。
文摘Ciphertext-Policy Attribute-Based Encryption(CP-ABE)enables fine-grained access control on ciphertexts,making it a promising approach for managing data stored in the cloud-enabled Internet of Things.But existing schemes often suffer from privacy breaches due to explicit attachment of access policies or partial hiding of critical attribute content.Additionally,resource-constrained IoT devices,especially those adopting wireless communication,frequently encounter affordability issues regarding decryption costs.In this paper,we propose an efficient and fine-grained access control scheme with fully hidden policies(named FHAC).FHAC conceals all attributes in the policy and utilizes bloom filters to efficiently locate them.A test phase before decryption is applied to assist authorized users in finding matches between their attributes and the access policy.Dictionary attacks are thwarted by providing unauthorized users with invalid values.The heavy computational overhead of both the test phase and most of the decryption phase is outsourced to two cloud servers.Additionally,users can verify the correctness of multiple outsourced decryption results simultaneously.Security analysis and performance comparisons demonstrate FHAC's effectiveness in protecting policy privacy and achieving efficient decryption.
文摘This paper presents 3RVAV(Three-Round Voting with Advanced Validation),a novel Byzantine Fault Tolerant consensus protocol combining Proof-of-Stake with a multi-phase voting mechanism.The protocol introduces three layers of randomized committee voting with distinct participant roles(Validators,Delegators,and Users),achieving(4/5)-threshold approval per round through a verifiable random function(VRF)-based selection process.Our security analysis demonstrates 3RVAV provides 1−(1−s/n)^(3k) resistance to Sybil attacks with n participants and stake s,while maintaining O(kn log n)communication complexity.Experimental simulations show 3247 TPS throughput with 4-s finality,representing a 5.8×improvement over Algorand’s committee-based approach.The proposed protocol achieves approximately 4.2-s finality,demonstrating low latency while maintaining strong consistency and resilience.The protocol introduces a novel punishment matrix incorporating both stake slashing and probabilistic blacklisting,proving a Nash equilibrium for honest participation under rational actor assumptions.
基金supported in part by the National Natural Science Foundation of China under Grants 62102450,62272478the Independent Research Project of a Certain Unit under Grant ZZKY20243127.
文摘Federated Learning(FL)has emerged as a promising distributed machine learning paradigm that enables multi-party collaborative training while eliminating the need for raw data sharing.However,its reliance on a server introduces critical security vulnerabilities:malicious servers can infer private information from received local model updates or deliberately manipulate aggregation results.Consequently,achieving verifiable aggregation without compromising client privacy remains a critical challenge.To address these problem,we propose a reversible data hiding in encrypted domains(RDHED)scheme,which designs joint secret message embedding and extraction mechanism.This approach enables clients to embed secret messages into ciphertext redundancy spaces generated during model encryption.During the server aggregation process,the embedded messages from all clients fuse within the ciphertext space to form a joint embedding message.Subsequently,clients can decrypt the aggregated results and extract this joint embedding message for verification purposes.Building upon this foundation,we integrate the proposed RDHED scheme with linear homomorphic hash and digital signatures to design a verifiable privacy-preserving aggregation protocol for single-server architectures(VPAFL).Theoretical proofs and experimental analyses show that VPAFL can effectively protect user privacy,achieve lightweight computational and communication overhead of users for verification,and present significant advantages with increasing model dimension.
基金supported by the National Cryptologic Science Fund of China(Grant No.2025NCSF02020)awarded to Yi Sunsupported by the Natural Science Foundation of Henan Province(Grant No.242300420297)awarded to Yi Sun。
文摘To enable efficient sharing of unbounded streaming data,this paper introduces blockchain technology into traditional cloud data,proposing a hybrid on-chain/off-chain storage model.We design a real-time verifiable data structure that is more suitable for streaming data to achieve efficient real-time verifiability for streaming data.Based on the notch gate hash function and vector commitment,an adaptive notch gate hash tree structure is constructed,and an efficient real-time verifiable data structure for on-chain and off-chain stream data is proposed.The structure binds dynamic root nodes sequentially to ordered leaf nodes in its child nodes.Only the vector commitment of the dynamic root node is stored on the chain,and the complete data structure is stored off-chain.This structure ensures tamperproofing against malicious off-chain cloud servers of off-chain cloud servers.Preserves storage scalability space,realizes the immediate verification of stream data upon arrival,and the computational overhead of on-chain and off-chain hybrid storage verification is only related to the current data volume,which is more practical when dealing with stream data with unpredictable data volume.We formalize this as an efficient real-time verification scheme for stream data in on-chain and off-chain hybrid storage.Finally,the technology’s security and performance were empirically validated through rigorous analysis.
基金The National High Technology Research and Development Program of China(863Program)(No.2001AA115300)the Natural Science Foundation of Liaoning Province(No.20031018,20062023)
文摘To prevent server compromise attack and password guessing attacks,an improved and efficient verifier-based key exchange protocol for three-party is proposed,which enables two clients to agree on a common session key with the help of the server.In this protocol,the client stores a plaintext version of the password,while the server stores a verifier for the password.And the protocol uses verifiers to authenticate between clients and the server.The security analysis and performance comparison of the proposed protocol shows that the protocol can resist many familiar attacks including password guessing attacks,server compromise attacks,man-in-the-middle attacks and Denning-Sacco attacks,and it is more efficient.
文摘According to the chloride corrosion environment,service life prediction model of concrete structure of sea-crossing bridge was built using modified Fick's second law and the whole probability calculation method,which was suitable for China. Furthermore,a visual service life prediction program of concrete structure was developed by optimized Monte Carlo method. Meanwhile,Life 365 program was compared,indicating reliability of the prediction program. Finally,the validity of prediction model was verified in JinTang Bridge of Zhoushan Island Mainland Linkage Project.
基金financially supported by the Fundamental Research Funds for the Central Universities(2572016CB11 and 2572014CB35)Natural Science Foundation of Heilongjiang Province(F2015036 and QC2014C010)948 Project(2014-4-78)
文摘The primary bottleneck to extracting wood defects during ultrasonic testing is the accuracy of identifying the wood defects. The wavelet energy moment was used to extract defect features of artificial wood holes drilled into 120 elm samples that differed in the number of holes to verify the validity of the method. Wavelet energy moment can reflect the distribution of energy along the time axis and the amount of energy in each frequency band,which can effectively extract the energy distribution characteristics of signals in each frequency band; therefore,wavelet energy moment can replace the wavelet frequency band energy and constitute wood defect feature vectors. A principal component analysis was used to normalize and reduce the dimension of the feature vectors. A total of 16 principal component features were then obtained, which can effectively extract the defect features of the different number of holes in the elm samples.
基金Supported by the National Basic Research Program of China under Grant No 2012CB825601the National Natural Science Foundation of China under Grant Nos 40921063,41031066,40890162,40904050,41074121 and 41074122the Specialized Research Fund for State Key Laboratories.
文摘We present a new hybrid numerical scheme for two-dimensional(2D)ideal magnetohydrodynamic(MHD)equations.A simple conservation element and solution element(CESE)method is used to calculate the flow variables,and the unknown first-order spatial derivatives involved in the CESE method are computed with a finite volume scheme that uses the solution of the derivative Riemann problem with limited reconstruction to evaluate the numerical flux at cell interface position.To show the validation and capacity of its application to 2D MHD problems,we study several benchmark problems.Numerical results verify that the hybrid scheme not only performs well,but also can retain the solution quality even if the Courant number ranges from close to 1 to less than 0.01.
基金Supported by the Natural Science Foundation of Shandong Province under Grant No ZR2010GL013.
文摘We investigate the synchronization and anti-synchronization of the new 4D chaotic system and propose a same adaptive controller in the form which not only synchronizes,but also anti-synchronizes two identical new 4D chaotic systems.Numerical simulations verify the correctness and the effectiveness of the proposed theoretical results.
基金by the National Natural Science Foundation of China under Grant No 61077004the Science Foundation of Education Commission of Beijing under Grant No KZ200910005001Innovative Talent and Team Development for Serving Beijing.
文摘Digital holographic microscopy has been a powerful metrological technique for phase-contrast imaging.However inherent phase aberrations always exist and degrade the quality of the phase-contrast images.A surface fitting method based on an improved mathematic model is proposed,which can be used to remove the phase aberrations without any pre-knowledge of the setup or manual operation.The improved mathematic model includes not only the usual terms but also the cross terms and the high order terms to describe the phase aberrations with high accuracy.Meanwhile,a non-iterative algorithm is used to solve the parametersand thus less computational load is imposed.The proposed method is applied to the live imaging of cells.The experimental results verify its validity.
基金financially supported by the Post Innovation Program of the Fisheries Science Institute of Chonnam National University
文摘This study describes an automatic berthing system with mooring lines. It is designed to be berthed by using mooring device on the upper deck of a ship. It is to berth once maintaining parallel with the quay by controlling both forward and aft breast lines. Berthing method is used through length adjustment of mooring lines connected between ship and quay by controlling the angular velocity and the torque of hydraulic motor in mooring device. The study is conducted under three changing conditions of draft, such as even-keel, rise of the gravity center and trim to stern. Variables affecting berthing stability are determined based on the control performance of each condition. Bond graphs method is used to model the system. Controller is designed as PID control method of reference-model algorithm. The control program is composed of synchronous control system based on the equations derived with the numerical analysis. The tank test is conducted to verify the usefulness of the control program.
文摘BACKGROUND Peripherally inserted central catheters(PICCs)are commonly used in hospitalized patients with liver cancer for the administration of chemotherapy,nutrition,and other medications.However,PICC-related thrombosis is a serious complication that can lead to morbidity and mortality in this patient population.Several risk factors have been identified for the development of PICC-related thrombosis,including cancer type,stage,comorbidities,and catheter characteristics.Understanding these risk factors and developing a predictive model can help healthcare providers identify high-risk patients and implement preventive measures to reduce the incidence of thrombosis.AIM To analyze the influencing factors of PICC-related thrombosis in hospitalized patients with liver cancer,construct a predictive model,and validate it.METHODS Clinical data of hospitalized patients with liver cancer admitted from January 2020 to December 2023 were collected.Thirty-five cases of PICC-related thrombosis in hospitalized patients with liver cancer were collected,and 220 patients who underwent PICC placement during the same period but did not develop PICC-related thrombosis were randomly selected as controls.A total of 255 samples were collected and used as the training set,and 77 cases were collected as the validation set in a 7:3 ratio.General patient information,case data,catheterization data,coagulation indicators,and Autar Thrombosis Risk Assessment Scale scores were analyzed.Univariate and multivariate unconditional logistic regression analyses were performed on relevant factors,and the value of combined indicators in predicting PICC-related thrombosis in hospitalized patients with liver cancer was evaluated using receiver operating characteristic(ROC)curve analysis.RESULTS Univariate analysis showed statistically significant differences(P<0.05)in age,sex,Karnofsky performance status score(KPS),bedridden time,activities of daily living impairment,parenteral nutrition,catheter duration,distant metastasis,and bone marrow suppression between the thrombosis group and the non-thrombosis group.Other aspects had no statistically significant differences(P>0.05).Multivariate regression analysis showed that age≥60 years,KPS score≤50 points,parenteral nutrition,stage III to IV,distant metastasis,bone marrow suppression,and activities of daily living impairment were independent risk factors for PICC-related thrombosis in hospitalized patients with liver cancer(P<0.05).Catheter duration of 1-6 months and catheter duration>6 months were protective factors for PICC-related thrombosis(P<0.05).The predictive model for PICC-related thrombosis was obtained as follows:P predictive probability=[exp(Logit P)]/[1+exp(Logit P)],where Logit P=age×1.907+KPS score×2.045+parenteral nutrition×9.467+catheter duration×0.506+tumor-node-metastasis(TNM)staging×2.844+distant metastasis×2.065+bone marrow suppression×2.082+activities of daily living impairment×13.926.ROC curve analysis showed an area under the curve(AUC)of 0.827(95%CI:0.724-0.929,P<0.001),with a corresponding optimal cut-off value of 0.612,sensitivity of 0.755,and specificity of 0.857.Calibration curve analysis showed good consistency between the predicted occurrence of PICC-related thrombosis and actual occurrence(P>0.05).ROC analysis showed AUCs of 0.888 and 0.729 for the training and validation sets,respectively.CONCLUSION Age,KPS score,parenteral nutrition,TNM staging,distant metastasis,bone marrow suppression,and activities of daily living impairment are independent risk factors for PICC-related thrombosis in hospitalized patients with liver cancer,while catheter duration is a protective factor for the disease.The predictive model has an AUC of 0.827,indicating high predictive accuracy and clinical value.
