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
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
Flow-based measurement is a popular method for various network monitoring usages.However, many flow exporting softwares have still low performance to collect all flows.In this paper, we propose a IPFIX-based flow expo...Flow-based measurement is a popular method for various network monitoring usages.However, many flow exporting softwares have still low performance to collect all flows.In this paper, we propose a IPFIX-based flow export engine with an enhanced and extensible data structure, called XFix, on the basis of a GPL tool,-nProbe.In the engine, we use an extensible two-dimensional hash table for flow aggregation, which is able to improve the performance of the metering process as well as support bidirectional flow.Experimental results have shown its efficiency in multi-thread processing activity.展开更多
With development of electronic com- merce, non-repudiation protocol as the basal component of non-repudiation service has done more and more important functions. Comparing with lots of work on two-party non-repudiatio...With development of electronic com- merce, non-repudiation protocol as the basal component of non-repudiation service has done more and more important functions. Comparing with lots of work on two-party non-repudiation, there are less work on multi-party non-repudiation protocol. Multi-party protocol is more complex and facing more challenge of collusion attack. In this paper we give a kind of multi-party non-repudiation protocol based on off-line TTP with consistent evidence. Consistent evidence is a property that can not only simplify the process of disputation resolving, but also make the service more friendly to users, which means that whether or not TTP involves, evidences participants obtained are consistent. In the meanwhile we analyze the collusion attack that multi-party protocol facing, our protocol can prevent collusion attack.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。
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.
文摘Flow-based measurement is a popular method for various network monitoring usages.However, many flow exporting softwares have still low performance to collect all flows.In this paper, we propose a IPFIX-based flow export engine with an enhanced and extensible data structure, called XFix, on the basis of a GPL tool,-nProbe.In the engine, we use an extensible two-dimensional hash table for flow aggregation, which is able to improve the performance of the metering process as well as support bidirectional flow.Experimental results have shown its efficiency in multi-thread processing activity.
文摘With development of electronic com- merce, non-repudiation protocol as the basal component of non-repudiation service has done more and more important functions. Comparing with lots of work on two-party non-repudiation, there are less work on multi-party non-repudiation protocol. Multi-party protocol is more complex and facing more challenge of collusion attack. In this paper we give a kind of multi-party non-repudiation protocol based on off-line TTP with consistent evidence. Consistent evidence is a property that can not only simplify the process of disputation resolving, but also make the service more friendly to users, which means that whether or not TTP involves, evidences participants obtained are consistent. In the meanwhile we analyze the collusion attack that multi-party protocol facing, our protocol can prevent collusion attack.
