电子邮件网络作为社会网络的一种形态,能反映人们的社交关系,对其展开研究有重要的社会意义。首先基于复杂网络理论构建了邮件网络的拓扑模型,分析了邮件网络的拓扑特性,在此基础上提出了一种基于点权和边权(Weight of Node and Edge,W...电子邮件网络作为社会网络的一种形态,能反映人们的社交关系,对其展开研究有重要的社会意义。首先基于复杂网络理论构建了邮件网络的拓扑模型,分析了邮件网络的拓扑特性,在此基础上提出了一种基于点权和边权(Weight of Node and Edge,WNE)的邮件网络搜索策略。最后通过实验验证了该策略在搜索代价上优于广度优先、随机游走和最大度搜索策略这三种现有搜索策略,验证了其合理性和有效性。展开更多
Connectivity is the premise and foundation of networking and routing.For the probabilistic flight path of military aircraft resulting in the difficulty of Aeronautical Ad hoc NETwork(AANET) research,an estimation meth...Connectivity is the premise and foundation of networking and routing.For the probabilistic flight path of military aircraft resulting in the difficulty of Aeronautical Ad hoc NETwork(AANET) research,an estimation method of connectivity probability is proposed.The method takes airspace as the research object,starts with actual flight characteristics,and applies conclusions of random waypoint mobility model.Building a connectivity model by establishing Airspace Unit Circle(AUC) from the perspective of circle-circle coverage,the method obtains a theory of airspace network connectivity.Experiment demonstrates its correctness.Finally,according to the actual condition simulation,relationship between the number of aircraft,communication radius,and the flight area under connectivity probabilities is achieved,results provide reference for creating a network that under certain aerial combat condition.展开更多
According to the security shortages of two robust practical email protocols with perfect forward secrecy, attacks on the two protocols are analyzed and corresponding improvements on the two protocols are proposed. Fir...According to the security shortages of two robust practical email protocols with perfect forward secrecy, attacks on the two protocols are analyzed and corresponding improvements on the two protocols are proposed. First, by analyzing the two email protocols, the corresponding man-in-the-middle attacks are proposed, where the adversary forges the messages in the receiving phase to cheat the two communication participants and makes them share the wrong session keys with him. Consequently, the man-in-the-middle attacks can make the two protocols fail to provide perfect forward secrecy. Secondly, by adding corresponding signatures in the receiving phases of the two protocols, two corresponding improvements on the protocols are proposed to overcome the man-in-the-middle attacks on the two protocols and make them provide perfect forward secrecy. Moreover, the two improved protocols can retain all the merits of the former protocols.展开更多
In order to achieve fast synchronization of the modulation hopping system, a synchronization scheme called short code to guide long code is adopted, and the initial synchronization hops and service hops are designed i...In order to achieve fast synchronization of the modulation hopping system, a synchronization scheme called short code to guide long code is adopted, and the initial synchronization hops and service hops are designed in detail.According to the system requirements for short code in the properties of time-varying, safety and balance, an algorithm to design wide-gap chaos short code based on TOD is proposed.Synchronization performance analysis shows that the algorithm has good performance, the initial synchronization time and the later entering network synchronization time are short, additionally, maximum synchronization time difference and synchronization maintaining time are long, all of which meet the needs of normal communications, and further verify the synchronization scheme feasible.展开更多
Mobile multicast is important for the emerging applications such as mobile video or audio conference and mobile IPTV.Some mobile multicast schemes have been proposed in the past few years, but most of them study the r...Mobile multicast is important for the emerging applications such as mobile video or audio conference and mobile IPTV.Some mobile multicast schemes have been proposed in the past few years, but most of them study the reconstruc-tion of multicast delivery tree, and few consider the group membership management for mobile sub-scribers.In this paper, we propose a new mobile multicast method based on the Two-Hop Multicast Listener Discovery(THMLD) protocol which pro-vides the mobile multicast membership manage-ment function by forwarding the traditional MLD messages to its neighboring subnets.To evaluate its performance, we analyze the THMLD and set up the simulation platform to compare it with the several traditional mobile multicast methods.The results show that THMLD can reduce the multicast join time, and the THMLD-based mobile multicast method can reduce the multicast join delay at a cost of increasing additional multicast maintenance cost.展开更多
For the published block cipher algorithm, two kinds of round functions have been researched.Block ciphers in network environments are taking more risks than ever before because of their initialization key's distri...For the published block cipher algorithm, two kinds of round functions have been researched.Block ciphers in network environments are taking more risks than ever before because of their initialization key's distribution in the internet.The security of block cipher algorithm is affected by linear bias and nonlinear bias which are restricted by confusion layer and diffusion layer.This article takes an approach on how block cipher's two round structures are initially transformed when they fuse into LFSR.The SP structure can be considered two F functions in one Feistel round function which combines both right and left of origin data transformation.Furthermore, the round number linear function and nonlinear function of Feistel and SP structure are compared.The merit of SP structure is that it can fuse in LFSR as a nonlinear filter without memory.展开更多
In this paper,an Adaptive-Weighted Time-Dimensional and Space-Dimensional(AWTDSD) data aggregation algorithm for a clustered sensor network is proposed for prolonging the lifetime of the network as well as improving t...In this paper,an Adaptive-Weighted Time-Dimensional and Space-Dimensional(AWTDSD) data aggregation algorithm for a clustered sensor network is proposed for prolonging the lifetime of the network as well as improving the accuracy of the data gathered in the network.AWTDSD contains three phases:(1) the time-dimensional aggregation phase for eliminating the data redundancy;(2) the adaptive-weighted aggregation phase for further aggregating the data as well as improving the accuracy of the aggregated data; and(3) the space-dimensional aggregation phase for reducing the size and the amount of the data transmission to the base station.AWTDSD utilizes the correlations between the sensed data for reducing the data transmission and increasing the data accuracy as well.Experimental result shows that AWTDSD can not only save almost a half of the total energy consumption but also greatly increase the accuracy of the data monitored by the sensors in the clustered network.展开更多
文摘电子邮件网络作为社会网络的一种形态,能反映人们的社交关系,对其展开研究有重要的社会意义。首先基于复杂网络理论构建了邮件网络的拓扑模型,分析了邮件网络的拓扑特性,在此基础上提出了一种基于点权和边权(Weight of Node and Edge,WNE)的邮件网络搜索策略。最后通过实验验证了该策略在搜索代价上优于广度优先、随机游走和最大度搜索策略这三种现有搜索策略,验证了其合理性和有效性。
文摘Connectivity is the premise and foundation of networking and routing.For the probabilistic flight path of military aircraft resulting in the difficulty of Aeronautical Ad hoc NETwork(AANET) research,an estimation method of connectivity probability is proposed.The method takes airspace as the research object,starts with actual flight characteristics,and applies conclusions of random waypoint mobility model.Building a connectivity model by establishing Airspace Unit Circle(AUC) from the perspective of circle-circle coverage,the method obtains a theory of airspace network connectivity.Experiment demonstrates its correctness.Finally,according to the actual condition simulation,relationship between the number of aircraft,communication radius,and the flight area under connectivity probabilities is achieved,results provide reference for creating a network that under certain aerial combat condition.
基金The Natural Science Foundation of Jiangsu Province(No.BK2006108)
文摘According to the security shortages of two robust practical email protocols with perfect forward secrecy, attacks on the two protocols are analyzed and corresponding improvements on the two protocols are proposed. First, by analyzing the two email protocols, the corresponding man-in-the-middle attacks are proposed, where the adversary forges the messages in the receiving phase to cheat the two communication participants and makes them share the wrong session keys with him. Consequently, the man-in-the-middle attacks can make the two protocols fail to provide perfect forward secrecy. Secondly, by adding corresponding signatures in the receiving phases of the two protocols, two corresponding improvements on the protocols are proposed to overcome the man-in-the-middle attacks on the two protocols and make them provide perfect forward secrecy. Moreover, the two improved protocols can retain all the merits of the former protocols.
基金supported by the Doctor Sustention Foundation of Telecommunication Engineering Institute,Air Force Engineering University (No.KDYBSJJ08605)the Key Laboratory Foundation of National Defense Science and Technology (No.9140c860302)
文摘In order to achieve fast synchronization of the modulation hopping system, a synchronization scheme called short code to guide long code is adopted, and the initial synchronization hops and service hops are designed in detail.According to the system requirements for short code in the properties of time-varying, safety and balance, an algorithm to design wide-gap chaos short code based on TOD is proposed.Synchronization performance analysis shows that the algorithm has good performance, the initial synchronization time and the later entering network synchronization time are short, additionally, maximum synchronization time difference and synchronization maintaining time are long, all of which meet the needs of normal communications, and further verify the synchronization scheme feasible.
基金supported in part by 973 program under con-tract 2007CB307101National High Technology of China ("863 program") under contract No. 2008AA01A326 National Natural Science Foundation of China under Grant No. 60870015 and No. 60833002
文摘Mobile multicast is important for the emerging applications such as mobile video or audio conference and mobile IPTV.Some mobile multicast schemes have been proposed in the past few years, but most of them study the reconstruc-tion of multicast delivery tree, and few consider the group membership management for mobile sub-scribers.In this paper, we propose a new mobile multicast method based on the Two-Hop Multicast Listener Discovery(THMLD) protocol which pro-vides the mobile multicast membership manage-ment function by forwarding the traditional MLD messages to its neighboring subnets.To evaluate its performance, we analyze the THMLD and set up the simulation platform to compare it with the several traditional mobile multicast methods.The results show that THMLD can reduce the multicast join time, and the THMLD-based mobile multicast method can reduce the multicast join delay at a cost of increasing additional multicast maintenance cost.
文摘For the published block cipher algorithm, two kinds of round functions have been researched.Block ciphers in network environments are taking more risks than ever before because of their initialization key's distribution in the internet.The security of block cipher algorithm is affected by linear bias and nonlinear bias which are restricted by confusion layer and diffusion layer.This article takes an approach on how block cipher's two round structures are initially transformed when they fuse into LFSR.The SP structure can be considered two F functions in one Feistel round function which combines both right and left of origin data transformation.Furthermore, the round number linear function and nonlinear function of Feistel and SP structure are compared.The merit of SP structure is that it can fuse in LFSR as a nonlinear filter without memory.
基金Supported by the Promotive Research Fund for Excellent Young and Middle-aged Scientists of Shandong Province(No.BS2010DX010)the Project of Higher Educational Science and Technology Program of Shandong Province(No.J12LN36)
文摘In this paper,an Adaptive-Weighted Time-Dimensional and Space-Dimensional(AWTDSD) data aggregation algorithm for a clustered sensor network is proposed for prolonging the lifetime of the network as well as improving the accuracy of the data gathered in the network.AWTDSD contains three phases:(1) the time-dimensional aggregation phase for eliminating the data redundancy;(2) the adaptive-weighted aggregation phase for further aggregating the data as well as improving the accuracy of the aggregated data; and(3) the space-dimensional aggregation phase for reducing the size and the amount of the data transmission to the base station.AWTDSD utilizes the correlations between the sensed data for reducing the data transmission and increasing the data accuracy as well.Experimental result shows that AWTDSD can not only save almost a half of the total energy consumption but also greatly increase the accuracy of the data monitored by the sensors in the clustered network.
