Multi-server authenticated key agreement schemes have attracted great attention to both academia and industry in recent years.However,traditional authenticated key agreement schemes in the single-server environment ar...Multi-server authenticated key agreement schemes have attracted great attention to both academia and industry in recent years.However,traditional authenticated key agreement schemes in the single-server environment are not suitable for the multi-server environment because the user has to register on each server when he/she wishes to log in various servers for different service.Moreover,it is unreasonable to consider all servers are trusted since the server in a multi-server environment may be a semi-trusted party.In order to overcome these difficulties,we designed a secure three-factor multi-server authenticated key agreement protocol based on elliptic curve cryptography,which needs the user to register only once at the registration center in order to access all semi-trusted servers.The proposed scheme can not only against various known attacks but also provides high computational efficiency.Besides,we have proved our scheme fulfills mutual authentication by using the authentication test method.展开更多
During the past decade,rapid advances in wireless communication technologies have made it possible for users to access desired services using hand-held devices.Service providers have hosted multiple servers to ensure ...During the past decade,rapid advances in wireless communication technologies have made it possible for users to access desired services using hand-held devices.Service providers have hosted multiple servers to ensure seamless online services to end-users.To ensure the security of this online communication,researchers have proposed several multi-server authentication schemes incorporating various cryptographic primitives.Due to the low power and computational capacities of mobile devices,the hash-based multi-server authenticated key agreement schemes with offline Registration Server(RS)are the most efficient choice.Recently,Kumar-Om presented such a scheme and proved its security against all renowned attacks.However,we find that their scheme bears an incorrect login phase,and is unsafe to the trace attack,the Session-Specific Temporary Information Attack(SSTIA),and the Key Compromise Impersonation Attack(KCIA).In fact,all of the existing multi-server authentication schemes(hash-based with offline RS)do not withstand KCLA.To deal with this situation,we propose an improved hash-based multi-server authentication scheme(with offline RS).We analyze the security of the proposed scheme under the random oracle model and use the t4Automated Validation of Internet Security Protocols and Applications''(AVISPA)tool.The comparative analysis of communication overhead and computational complexity metrics shows the efficiency of the proposed scheme.展开更多
In order to improve the infrared detection and discrimination ability of the smart munition to the dynamic armor target under the complex background,the multi-line array infrared detection system is established based ...In order to improve the infrared detection and discrimination ability of the smart munition to the dynamic armor target under the complex background,the multi-line array infrared detection system is established based on the combination of the single unit infrared detector.The surface dimension features of ground armored targets are identified by size calculating solution algorithm.The signal response value and the value of size calculating are identified by the method of fuzzy recognition to make the fuzzy classification judgment for armored target.According to the characteristics of the target signal,a custom threshold de-noising function is proposed to solve the problem of signal preprocessing.The multi-line array infrared detection can complete the scanning detection in a large area in a short time with the characteristics of smart munition in the steady-state scanning stage.The method solves the disadvantages of wide scanning interval and low detection probability of single unit infrared detection.By reducing the scanning interval,the number of random rendezvous in the infrared feature area of the upper surface is increased,the accuracy of the size calculating is guaranteed.The experiments results show that in the fuzzy recognition method,the size calculating is introduced as the feature operator,which can improve the recognition ability of the ground armor target with different shape size.展开更多
For the rapid calibration of multi-line structured light system,a method based on Plücker line was proposed.Most of the conventional line-structured light calibration methods extract the feature points and transf...For the rapid calibration of multi-line structured light system,a method based on Plücker line was proposed.Most of the conventional line-structured light calibration methods extract the feature points and transform the coordinates of points to obtain the plane equation.However,a large number of points lead to complicated operation which is not suitable for the application scenarios of multi-line structured light.To solve this issue,a new calibration method was proposed that applied the form of Plücker matrix throughout the whole calibration process,instead of using the point characteristics directly.The advantage of this method is that the light plane equation can be obtained quickly and accurately in the camera coordinate frame.Correspondingly a planar target particularly for calibrating multi-line structured light was also designed.The regular lines were transformed into Plücker lines by extending the two-dimensional image plane and defining a new image space.To transform the coordinate frame of Plücker lines,the perspective projection mathematical model was re-expressed based on the Plücker matrix.According to the properties of the line and plane in the Plücker space,a linear matrix equation was efficiently constructed by combining the Plücker matrices of several coplanar lines so that the line-structured light plane equation could be furtherly solved.The experiments performed validate the proposed method and demonstrate the significant improvement in the calibration accuracy,when the test distance is 1.8 m,the root mean square(RMS)error of the three-dimensional point is within 0.08 mm.展开更多
A low computational cost cancelable fingerprint template, namely the multi-line codes was proposed. The formulation of a single-line code involves the inspection of minutiae distribution along a straight line construc...A low computational cost cancelable fingerprint template, namely the multi-line codes was proposed. The formulation of a single-line code involves the inspection of minutiae distribution along a straight line constructed based on the reference minutia. Multi-line code is introduced to elevate the performance by combining several single-line codes. Experiments were carried out on a few FVC databases. It has been proven that the proposed method yields relatively low computational complexity as compared to existing minutiae distribution-based methods, while preserving the performance. The equal error rate obtained for FVC2002 DB1 is 4.69% in stolen-key case, and the total arithmetic operations utilized are 14 520 additions and zero multiplication.展开更多
Since network services are provided cooperatively by multiple servers in the lnternet, the authentication protocols for multiserver architecture are required by Internetbased services, such as online game, online trad...Since network services are provided cooperatively by multiple servers in the lnternet, the authentication protocols for multiserver architecture are required by Internetbased services, such as online game, online trade and so on. Recently, Li et al. analyzed Lee et al.'s protocol and proposed an improved dynamic identity based authentication protocol for multi-server architecture. They claimed that their protocol provides user's anonymity, mutual authentication and the session key agreement against several kinds of attacks. In this paper, a cryptanalysis on Lee et al.'s scheme shows that Lee et al's protocol is also vulnerable to malicious server attack, stolen smart card attack and leak-of-verifier attack. Moreover, Li e/ al.'s improved protocol is also vulnerable to all these attacks. Further cryptanalysis reveals that Li et al.'s improved protocol is susceptible to collusion attack.展开更多
With the development of communication technologies,various mobile devices and different types of mobile services became available.The emergence of these services has brought great convenience to our lives.The multi-se...With the development of communication technologies,various mobile devices and different types of mobile services became available.The emergence of these services has brought great convenience to our lives.The multi-server architecture authentication protocols for mobile cloud computing were proposed to ensure the security and availability between mobile devices and mobile services.However,most of the protocols did not consider the case of hierarchical authentication.In the existing protocol,when a mobile user once registered at the registration center,he/she can successfully authenticate with all mobile service providers that are registered at the registration center,but real application scenarios are not like this.For some specific scenarios,some mobile service providers want to provide service only for particular users.For this reason,we propose a new hierarchical multi-server authentication protocol for mobile cloud computing.The proposed protocol ensures only particular types of users can successfully authenticate with certain types of mobile service providers.The proposed protocol reduces computing and communication costs by up to 42.6%and 54.2%compared to two superior protocols.The proposed protocol can also resist the attacks known so far.展开更多
Adopted the distribution feedback type (DFB) laser to measure the coal mine gas methane, according to the methane located 1.6 μm nearby 2v3 with a R9 direct absorption spectrum, attraction wire intensity of each li...Adopted the distribution feedback type (DFB) laser to measure the coal mine gas methane, according to the methane located 1.6 μm nearby 2v3 with a R9 direct absorption spectrum, attraction wire intensity of each line was calculated through the multi-line Voigt fitting. The experimental result indicates that in the obtained four attraction recover of wire, the maximum deviation is 2.7%, and the minimum deviation is 0.02%, other results are all in experimental error scope. This research method may apply in the spectrum survey methane gas density, it has characteristics including high precision, strong selectivity, fast response and so on.展开更多
Currently, smart card based remote user authentication schemes have been widely adopted due to their low cost and convenient portability. With the purpose of using various different internet services with single regis...Currently, smart card based remote user authentication schemes have been widely adopted due to their low cost and convenient portability. With the purpose of using various different internet services with single registration and to protect the users from being tracked, various dynamic ID based multi-server authentication protocols have been proposed. Recently, Li et al. proposed an efficient and secure dynamic ID based authentication protocol using smart cards. They claimed that their protocol provides strong security. In this paper, we have demonstrated that Li et al.’s protocol is vulnerable to replay attack, denial of service attack, smart card lost attack, eavesdropping attack and server spoofing attacks.展开更多
In today’s information technology(IT)world,the multi-hop wireless sensor networks(MHWSNs)are considered the building block for the Internet of Things(IoT)enabled communication systems for controlling everyday tasks o...In today’s information technology(IT)world,the multi-hop wireless sensor networks(MHWSNs)are considered the building block for the Internet of Things(IoT)enabled communication systems for controlling everyday tasks of organizations and industry to provide quality of service(QoS)in a stipulated time slot to end-user over the Internet.Smart city(SC)is an example of one such application which can automate a group of civil services like automatic control of traffic lights,weather prediction,surveillance,etc.,in our daily life.These IoT-based networks with multi-hop communication and multiple sink nodes provide efficient communication in terms of performance parameters such as throughput,energy efficiency,and end-to-end delay,wherein low latency is considered a challenging issue in next-generation networks(NGN).This paper introduces a single and parallels stable server queuing model with amulti-class of packets and native and coded packet flowto illustrate the simple chain topology and complexmultiway relay(MWR)node with specific neighbor topology.Further,for improving data transmission capacity inMHWSNs,an analytical framework for packet transmission using network coding at the MWR node in the network layer with opportunistic listening is performed by considering bi-directional network flow at the MWR node.Finally,the accuracy of the proposed multi-server multi-class queuing model is evaluated with and without network coding at the network layer by transmitting data packets.The results of the proposed analytical framework are validated and proved effective by comparing these analytical results to simulation results.展开更多
In order to meet people’s demand for various types of network services,researchers have conducted extensive research on authentication schemes for multi-server architecture.Although various schemes have been proposed...In order to meet people’s demand for various types of network services,researchers have conducted extensive research on authentication schemes for multi-server architecture.Although various schemes have been proposed,most of them still have safety defects and fail to meet safety requirements.Recently,Haq et al presented an efficient Hash-based authenticated key agreement scheme for multi-server scheme and claimed that their scheme can withstand all well-known attacks.However,we find that their scheme is vulnerable to replay attack,tracking attack and malicious server impersonation user attack.Then we propose an improved scheme.We also analyze the security of the improved scheme and compare with Haq et al’s scheme in security and computational efficiency.Furthermore,we use the AVISPA(Automated Validation of Internet Security Protocols and Applications)tool to verify the security of the improved scheme.展开更多
When studying the harbor water tranquility, cases are often confronted as that the verification point is not located on the generation line or that the angle between the generation line and the isobath is so large tha...When studying the harbor water tranquility, cases are often confronted as that the verification point is not located on the generation line or that the angle between the generation line and the isobath is so large that the differences of the wave climates along the generation line can not be ignored. For these cases, the incident boundary conditions are difficult to evaluate. In order to solve this problem, a combined wave model is developed in the present paper based on the Boussinesq equation and the wave action balance equation. Instead of the one-line wave generation method, a multi-line generation method is proposed for the combined model. Application of this method is given to a case that the harbor is designed with two entrances and the angle between the generation line and the isobath is large and the results are shown reasonable. We suggest that the wave generation method on multi-lines might also be introduced to the wave physical model as the replacement for the one-line generation method.展开更多
With the advancement in internet technologies, the number of servers has increased remarkably to provide more services to the end users. These services are provided over the public channels, which are insecure and sus...With the advancement in internet technologies, the number of servers has increased remarkably to provide more services to the end users. These services are provided over the public channels, which are insecure and susceptible to interception, modification, and deletion. To provide security, registered entities are authenticated and then a session key is established between them to communicate securely. The conventional schemes anow a user to access services only after their independent registration with each desired server in a multiserver system. Therefore, a user must possess multiple smartcards and memorize various identities and passwords for obtaining services from multiple servers. This has led to the adoption of multiserver authentication in which a user accesses services of multiple servers after registering himself at only one central authority. Recently, Kumar and Om discussed a scheme for multiserver environment by using smartcard. Since the user-memorized passwords are of low entropy, it is possible for an attacker to guess them. This paper uses biometric information of user to enhance the security of the scheme by Kumar and Ore. Moreover, we conducted rigorous security analyses (informal and formal) in this study to prove the security of the proposed scheme against all known attacks. We also simulated our scheme by using the automated tool, ProVerif, to prove its secrecy and authentication properties. A comparative study of the proposed scheme with the existing related schemes shows its effectiveness.展开更多
The scheduling of parallel machines and the optimization of multi-line systems are two hotspots in the field of complex manufacturing systems.When the two problems are considered simultaneously,the resulting problem i...The scheduling of parallel machines and the optimization of multi-line systems are two hotspots in the field of complex manufacturing systems.When the two problems are considered simultaneously,the resulting problem is much more complex than either of them.Obtaining sufficient training data for conventional data-based optimization approaches is difficult because of the high diversity of system structures.Consequently,optimization of multi-line systems with alternative machines requires a simple mechanism and must be minimally dependent on historical data.To define a general multi-line system with alternative machines,this study introduces the capability vector and matrix and the distribution vector and matrix.A naive optimization method is proposed in accordance with classic feedback control theory,and its key approaches are introduced.When a reasonable target value is provided,the proposed method can realize closed-loop optimization to the selected objective performance.Case studies are performed on a real 5/6-inch semiconductor wafer manufacturing facility and a simulated multi-line system constructed on the basis of the MiniFAB model.Results show that the proposed method can effectively and efficiently optimize various objective performance.The method demonstrates a potential for utilization in multi-objective optimization.展开更多
The performance of an erbium-doped fiber ring laser based intra-cavity absorption gassensor was evaluated with performance enhanced techniques. A multi-line wavelength sweep techniqueand a weighted averaging technique...The performance of an erbium-doped fiber ring laser based intra-cavity absorption gassensor was evaluated with performance enhanced techniques. A multi-line wavelength sweep techniqueand a weighted averaging technique were proposed for better gas detection. By selecting appropriatesystem parameters, 6 strong absorption lines near 1 530 nm of C2H2 were obtained with good spectrumresolution in one scanning period. One group with higher absorption coefficients was used for relativelylow gas concentration detection and the other with lower absorption coefficients was used for relativelyhigh gas concentration. Both the groups can be used for medium gas concentration detection. For variousconcentration cases, by choosing proper absorption lines and performing weighted averaging, detectionaccuracy can be obtained over an extended detection range. The minimum detection limit could be verylow after optimization.展开更多
Most of the password based authentication protocols make use of the single authentication server for user's authentication. User's verifier information stored on the single server is a main point of susceptibi...Most of the password based authentication protocols make use of the single authentication server for user's authentication. User's verifier information stored on the single server is a main point of susceptibility and remains an attractive target for the attacker. On the other hand, multi-server architecture based authentication protocols make it difficult for the attacker to find out any significant authentication information related to the legitimate users. In 2009, Liao and Wang proposed a dynamic identity based remote user authentication protocol for multi-server environment. However, we found that Liao and Wang's protocol is susceptible to malicious server attack and malicious user attack. This paper presents a novel dynamic identity based authentication protocol for multi-server architecture using smart cards that resolves the aforementioned flaws, while keeping the merits of Liao and Wang's protocol. It uses two-server paradigm by imposing different levels of trust upon the two servers and the user's verifier information is distributed between these two servers known as the service provider server and the control server. The proposed protocol is practical and computational efficient because only nonce, one-way hash function and XOR operations are used in its implementation. It provides a secure method to change the user's password without the server's help. In e-commerce, the number of servers providing the services to the user is usually more than one and hence secure authentication protocols for multi-server environment are required.展开更多
基金This work is supported by the Sichuan education department research project(No.16226483)Sichuan Science and Technology Program(No.2018GZDZX0008)+1 种基金Chengdu Science and Technology Program(No.2018-YF08-00007-GX)the National Natural Science Foundation of China(No.61872087).
文摘Multi-server authenticated key agreement schemes have attracted great attention to both academia and industry in recent years.However,traditional authenticated key agreement schemes in the single-server environment are not suitable for the multi-server environment because the user has to register on each server when he/she wishes to log in various servers for different service.Moreover,it is unreasonable to consider all servers are trusted since the server in a multi-server environment may be a semi-trusted party.In order to overcome these difficulties,we designed a secure three-factor multi-server authenticated key agreement protocol based on elliptic curve cryptography,which needs the user to register only once at the registration center in order to access all semi-trusted servers.The proposed scheme can not only against various known attacks but also provides high computational efficiency.Besides,we have proved our scheme fulfills mutual authentication by using the authentication test method.
文摘During the past decade,rapid advances in wireless communication technologies have made it possible for users to access desired services using hand-held devices.Service providers have hosted multiple servers to ensure seamless online services to end-users.To ensure the security of this online communication,researchers have proposed several multi-server authentication schemes incorporating various cryptographic primitives.Due to the low power and computational capacities of mobile devices,the hash-based multi-server authenticated key agreement schemes with offline Registration Server(RS)are the most efficient choice.Recently,Kumar-Om presented such a scheme and proved its security against all renowned attacks.However,we find that their scheme bears an incorrect login phase,and is unsafe to the trace attack,the Session-Specific Temporary Information Attack(SSTIA),and the Key Compromise Impersonation Attack(KCIA).In fact,all of the existing multi-server authentication schemes(hash-based with offline RS)do not withstand KCLA.To deal with this situation,we propose an improved hash-based multi-server authentication scheme(with offline RS).We analyze the security of the proposed scheme under the random oracle model and use the t4Automated Validation of Internet Security Protocols and Applications''(AVISPA)tool.The comparative analysis of communication overhead and computational complexity metrics shows the efficiency of the proposed scheme.
基金This work was supported by the National Natural Science Foundation of China(No.11804263)the Program for Innovative Science and Research Team of Xi’an Technological University.
文摘In order to improve the infrared detection and discrimination ability of the smart munition to the dynamic armor target under the complex background,the multi-line array infrared detection system is established based on the combination of the single unit infrared detector.The surface dimension features of ground armored targets are identified by size calculating solution algorithm.The signal response value and the value of size calculating are identified by the method of fuzzy recognition to make the fuzzy classification judgment for armored target.According to the characteristics of the target signal,a custom threshold de-noising function is proposed to solve the problem of signal preprocessing.The multi-line array infrared detection can complete the scanning detection in a large area in a short time with the characteristics of smart munition in the steady-state scanning stage.The method solves the disadvantages of wide scanning interval and low detection probability of single unit infrared detection.By reducing the scanning interval,the number of random rendezvous in the infrared feature area of the upper surface is increased,the accuracy of the size calculating is guaranteed.The experiments results show that in the fuzzy recognition method,the size calculating is introduced as the feature operator,which can improve the recognition ability of the ground armor target with different shape size.
基金National Natural Science Foundation of China(No.51575388)。
文摘For the rapid calibration of multi-line structured light system,a method based on Plücker line was proposed.Most of the conventional line-structured light calibration methods extract the feature points and transform the coordinates of points to obtain the plane equation.However,a large number of points lead to complicated operation which is not suitable for the application scenarios of multi-line structured light.To solve this issue,a new calibration method was proposed that applied the form of Plücker matrix throughout the whole calibration process,instead of using the point characteristics directly.The advantage of this method is that the light plane equation can be obtained quickly and accurately in the camera coordinate frame.Correspondingly a planar target particularly for calibrating multi-line structured light was also designed.The regular lines were transformed into Plücker lines by extending the two-dimensional image plane and defining a new image space.To transform the coordinate frame of Plücker lines,the perspective projection mathematical model was re-expressed based on the Plücker matrix.According to the properties of the line and plane in the Plücker space,a linear matrix equation was efficiently constructed by combining the Plücker matrices of several coplanar lines so that the line-structured light plane equation could be furtherly solved.The experiments performed validate the proposed method and demonstrate the significant improvement in the calibration accuracy,when the test distance is 1.8 m,the root mean square(RMS)error of the three-dimensional point is within 0.08 mm.
文摘A low computational cost cancelable fingerprint template, namely the multi-line codes was proposed. The formulation of a single-line code involves the inspection of minutiae distribution along a straight line constructed based on the reference minutia. Multi-line code is introduced to elevate the performance by combining several single-line codes. Experiments were carried out on a few FVC databases. It has been proven that the proposed method yields relatively low computational complexity as compared to existing minutiae distribution-based methods, while preserving the performance. The equal error rate obtained for FVC2002 DB1 is 4.69% in stolen-key case, and the total arithmetic operations utilized are 14 520 additions and zero multiplication.
基金supported by the Key Program of NSFC-Guangdong Union Foundation under Grant No.U1135002Young Foundation of Humanities and Social Sciences of MOE (Ministry of Education in China) of under Grant No.11YJCZH160Foundation for Young Scientists of Jiangxi Province of China under Grant No.20133BCB23016
文摘Since network services are provided cooperatively by multiple servers in the lnternet, the authentication protocols for multiserver architecture are required by Internetbased services, such as online game, online trade and so on. Recently, Li et al. analyzed Lee et al.'s protocol and proposed an improved dynamic identity based authentication protocol for multi-server architecture. They claimed that their protocol provides user's anonymity, mutual authentication and the session key agreement against several kinds of attacks. In this paper, a cryptanalysis on Lee et al.'s scheme shows that Lee et al's protocol is also vulnerable to malicious server attack, stolen smart card attack and leak-of-verifier attack. Moreover, Li e/ al.'s improved protocol is also vulnerable to all these attacks. Further cryptanalysis reveals that Li et al.'s improved protocol is susceptible to collusion attack.
基金This work is funded by the Chengdu Science and Technology Bureau No.2016-XT00-00015-GXthe Civil Aviation Administration of China No.PSDSA201802.
文摘With the development of communication technologies,various mobile devices and different types of mobile services became available.The emergence of these services has brought great convenience to our lives.The multi-server architecture authentication protocols for mobile cloud computing were proposed to ensure the security and availability between mobile devices and mobile services.However,most of the protocols did not consider the case of hierarchical authentication.In the existing protocol,when a mobile user once registered at the registration center,he/she can successfully authenticate with all mobile service providers that are registered at the registration center,but real application scenarios are not like this.For some specific scenarios,some mobile service providers want to provide service only for particular users.For this reason,we propose a new hierarchical multi-server authentication protocol for mobile cloud computing.The proposed protocol ensures only particular types of users can successfully authenticate with certain types of mobile service providers.The proposed protocol reduces computing and communication costs by up to 42.6%and 54.2%compared to two superior protocols.The proposed protocol can also resist the attacks known so far.
基金the National Natural Science Foundation of China(50574005)Natural Science Foundation of Education Department of Anhui,China(2005KJ081)
文摘Adopted the distribution feedback type (DFB) laser to measure the coal mine gas methane, according to the methane located 1.6 μm nearby 2v3 with a R9 direct absorption spectrum, attraction wire intensity of each line was calculated through the multi-line Voigt fitting. The experimental result indicates that in the obtained four attraction recover of wire, the maximum deviation is 2.7%, and the minimum deviation is 0.02%, other results are all in experimental error scope. This research method may apply in the spectrum survey methane gas density, it has characteristics including high precision, strong selectivity, fast response and so on.
文摘Currently, smart card based remote user authentication schemes have been widely adopted due to their low cost and convenient portability. With the purpose of using various different internet services with single registration and to protect the users from being tracked, various dynamic ID based multi-server authentication protocols have been proposed. Recently, Li et al. proposed an efficient and secure dynamic ID based authentication protocol using smart cards. They claimed that their protocol provides strong security. In this paper, we have demonstrated that Li et al.’s protocol is vulnerable to replay attack, denial of service attack, smart card lost attack, eavesdropping attack and server spoofing attacks.
文摘In today’s information technology(IT)world,the multi-hop wireless sensor networks(MHWSNs)are considered the building block for the Internet of Things(IoT)enabled communication systems for controlling everyday tasks of organizations and industry to provide quality of service(QoS)in a stipulated time slot to end-user over the Internet.Smart city(SC)is an example of one such application which can automate a group of civil services like automatic control of traffic lights,weather prediction,surveillance,etc.,in our daily life.These IoT-based networks with multi-hop communication and multiple sink nodes provide efficient communication in terms of performance parameters such as throughput,energy efficiency,and end-to-end delay,wherein low latency is considered a challenging issue in next-generation networks(NGN).This paper introduces a single and parallels stable server queuing model with amulti-class of packets and native and coded packet flowto illustrate the simple chain topology and complexmultiway relay(MWR)node with specific neighbor topology.Further,for improving data transmission capacity inMHWSNs,an analytical framework for packet transmission using network coding at the MWR node in the network layer with opportunistic listening is performed by considering bi-directional network flow at the MWR node.Finally,the accuracy of the proposed multi-server multi-class queuing model is evaluated with and without network coding at the network layer by transmitting data packets.The results of the proposed analytical framework are validated and proved effective by comparing these analytical results to simulation results.
基金Supported by the Applied Basic and Advanced Technology Research Programs of Tianjin(15JCYBJC15900)。
文摘In order to meet people’s demand for various types of network services,researchers have conducted extensive research on authentication schemes for multi-server architecture.Although various schemes have been proposed,most of them still have safety defects and fail to meet safety requirements.Recently,Haq et al presented an efficient Hash-based authenticated key agreement scheme for multi-server scheme and claimed that their scheme can withstand all well-known attacks.However,we find that their scheme is vulnerable to replay attack,tracking attack and malicious server impersonation user attack.Then we propose an improved scheme.We also analyze the security of the improved scheme and compare with Haq et al’s scheme in security and computational efficiency.Furthermore,we use the AVISPA(Automated Validation of Internet Security Protocols and Applications)tool to verify the security of the improved scheme.
基金supported by the National Natural Science Foundation of China(Grant No.50921001)
文摘When studying the harbor water tranquility, cases are often confronted as that the verification point is not located on the generation line or that the angle between the generation line and the isobath is so large that the differences of the wave climates along the generation line can not be ignored. For these cases, the incident boundary conditions are difficult to evaluate. In order to solve this problem, a combined wave model is developed in the present paper based on the Boussinesq equation and the wave action balance equation. Instead of the one-line wave generation method, a multi-line generation method is proposed for the combined model. Application of this method is given to a case that the harbor is designed with two entrances and the angle between the generation line and the isobath is large and the results are shown reasonable. We suggest that the wave generation method on multi-lines might also be introduced to the wave physical model as the replacement for the one-line generation method.
文摘With the advancement in internet technologies, the number of servers has increased remarkably to provide more services to the end users. These services are provided over the public channels, which are insecure and susceptible to interception, modification, and deletion. To provide security, registered entities are authenticated and then a session key is established between them to communicate securely. The conventional schemes anow a user to access services only after their independent registration with each desired server in a multiserver system. Therefore, a user must possess multiple smartcards and memorize various identities and passwords for obtaining services from multiple servers. This has led to the adoption of multiserver authentication in which a user accesses services of multiple servers after registering himself at only one central authority. Recently, Kumar and Om discussed a scheme for multiserver environment by using smartcard. Since the user-memorized passwords are of low entropy, it is possible for an attacker to guess them. This paper uses biometric information of user to enhance the security of the scheme by Kumar and Ore. Moreover, we conducted rigorous security analyses (informal and formal) in this study to prove the security of the proposed scheme against all known attacks. We also simulated our scheme by using the automated tool, ProVerif, to prove its secrecy and authentication properties. A comparative study of the proposed scheme with the existing related schemes shows its effectiveness.
基金This research was supported in part by the National Natural Science Foundation of China(Grant No.71690230/71690234)the International S&T Cooperation Program of China(Grant No.2017YFE0101400).
文摘The scheduling of parallel machines and the optimization of multi-line systems are two hotspots in the field of complex manufacturing systems.When the two problems are considered simultaneously,the resulting problem is much more complex than either of them.Obtaining sufficient training data for conventional data-based optimization approaches is difficult because of the high diversity of system structures.Consequently,optimization of multi-line systems with alternative machines requires a simple mechanism and must be minimally dependent on historical data.To define a general multi-line system with alternative machines,this study introduces the capability vector and matrix and the distribution vector and matrix.A naive optimization method is proposed in accordance with classic feedback control theory,and its key approaches are introduced.When a reasonable target value is provided,the proposed method can realize closed-loop optimization to the selected objective performance.Case studies are performed on a real 5/6-inch semiconductor wafer manufacturing facility and a simulated multi-line system constructed on the basis of the MiniFAB model.Results show that the proposed method can effectively and efficiently optimize various objective performance.The method demonstrates a potential for utilization in multi-objective optimization.
文摘The performance of an erbium-doped fiber ring laser based intra-cavity absorption gassensor was evaluated with performance enhanced techniques. A multi-line wavelength sweep techniqueand a weighted averaging technique were proposed for better gas detection. By selecting appropriatesystem parameters, 6 strong absorption lines near 1 530 nm of C2H2 were obtained with good spectrumresolution in one scanning period. One group with higher absorption coefficients was used for relativelylow gas concentration detection and the other with lower absorption coefficients was used for relativelyhigh gas concentration. Both the groups can be used for medium gas concentration detection. For variousconcentration cases, by choosing proper absorption lines and performing weighted averaging, detectionaccuracy can be obtained over an extended detection range. The minimum detection limit could be verylow after optimization.
文摘Most of the password based authentication protocols make use of the single authentication server for user's authentication. User's verifier information stored on the single server is a main point of susceptibility and remains an attractive target for the attacker. On the other hand, multi-server architecture based authentication protocols make it difficult for the attacker to find out any significant authentication information related to the legitimate users. In 2009, Liao and Wang proposed a dynamic identity based remote user authentication protocol for multi-server environment. However, we found that Liao and Wang's protocol is susceptible to malicious server attack and malicious user attack. This paper presents a novel dynamic identity based authentication protocol for multi-server architecture using smart cards that resolves the aforementioned flaws, while keeping the merits of Liao and Wang's protocol. It uses two-server paradigm by imposing different levels of trust upon the two servers and the user's verifier information is distributed between these two servers known as the service provider server and the control server. The proposed protocol is practical and computational efficient because only nonce, one-way hash function and XOR operations are used in its implementation. It provides a secure method to change the user's password without the server's help. In e-commerce, the number of servers providing the services to the user is usually more than one and hence secure authentication protocols for multi-server environment are required.