As the information technology rapidly develops,many network applications appear and their communication protocols are unknown.Although many protocol keyword recognition based protocol reverse engineering methods have ...As the information technology rapidly develops,many network applications appear and their communication protocols are unknown.Although many protocol keyword recognition based protocol reverse engineering methods have been proposed,most of the keyword recognition algorithms are time consuming.This paper firstly uses the traffic clustering method F-DBSCAN to cluster the unknown protocol traffic.Then an improved CFSM(Closed Frequent Sequence Mining)algorithm is used to mine closed frequent sequences from the messages and identify protocol keywords.Finally,CFGM(Closed Frequent Group Mining)algorithm is proposed to explore the parallel,sequential and hierarchical relations between the protocol keywords and obtain accurate protocol message formats.Experimental results show that the proposed protocol formats extraction method is better than Apriori algorithm and Sequence alignment algorithm in terms of time complexity and it can achieve high keyword recognition accuracy.Additionally,based on the relations between the keywords,the method can obtain accurate protocol formats.Compared with the protocol formats obtained from the existing methods,our protocol format can better grasp the overall structure of target protocols and the results perform better in the application of protocol reverse engineering such as fuzzing test.展开更多
This paper investigates formal techniques of protocol based on communicating finite state machines (CFSM). Taking the protocols POLLEND (PE) and ACKNACK (AN) as the examples, the paper discusses the formal description...This paper investigates formal techniques of protocol based on communicating finite state machines (CFSM). Taking the protocols POLLEND (PE) and ACKNACK (AN) as the examples, the paper discusses the formal description, validation and conversion of protocol with the CFSM, presents a protocol validation method and a protocol conversion algorithm based on the CFSM and demonstrates the applicability of the method and the algorithm using the example protocols PE and AN.展开更多
Bubble functions are finite element modes that are zero on the boundary of the element but nonzero at the other point. The present paper adds bubble functions to the ordinary Complex Finite Strip Method(CFSM) to calcu...Bubble functions are finite element modes that are zero on the boundary of the element but nonzero at the other point. The present paper adds bubble functions to the ordinary Complex Finite Strip Method(CFSM) to calculate the elastic local buckling stress of plates and plate assemblies. The results indicate that the use of bubble functions greatly improves the convergence of the Finite Strip Method(FSM) in terms of strip subdivision, and leads to much smaller storage required for the structure stiffness and stability matrices. Numerical examples are given, including plates and plate structures subjected to a combination of longitudinal and transverse compression, bending and shear. This study illustrates the power of bubble functions in solving stability problems of plates and plate structures.展开更多
基金supported by the National Key R&D Subsidized Project with 2017YFB0802900.
文摘As the information technology rapidly develops,many network applications appear and their communication protocols are unknown.Although many protocol keyword recognition based protocol reverse engineering methods have been proposed,most of the keyword recognition algorithms are time consuming.This paper firstly uses the traffic clustering method F-DBSCAN to cluster the unknown protocol traffic.Then an improved CFSM(Closed Frequent Sequence Mining)algorithm is used to mine closed frequent sequences from the messages and identify protocol keywords.Finally,CFGM(Closed Frequent Group Mining)algorithm is proposed to explore the parallel,sequential and hierarchical relations between the protocol keywords and obtain accurate protocol message formats.Experimental results show that the proposed protocol formats extraction method is better than Apriori algorithm and Sequence alignment algorithm in terms of time complexity and it can achieve high keyword recognition accuracy.Additionally,based on the relations between the keywords,the method can obtain accurate protocol formats.Compared with the protocol formats obtained from the existing methods,our protocol format can better grasp the overall structure of target protocols and the results perform better in the application of protocol reverse engineering such as fuzzing test.
文摘This paper investigates formal techniques of protocol based on communicating finite state machines (CFSM). Taking the protocols POLLEND (PE) and ACKNACK (AN) as the examples, the paper discusses the formal description, validation and conversion of protocol with the CFSM, presents a protocol validation method and a protocol conversion algorithm based on the CFSM and demonstrates the applicability of the method and the algorithm using the example protocols PE and AN.
基金the Natural Science Foundation of Jiangxi Province of Chinathe Basic Theory Research Foundation of Nanchang University
文摘Bubble functions are finite element modes that are zero on the boundary of the element but nonzero at the other point. The present paper adds bubble functions to the ordinary Complex Finite Strip Method(CFSM) to calculate the elastic local buckling stress of plates and plate assemblies. The results indicate that the use of bubble functions greatly improves the convergence of the Finite Strip Method(FSM) in terms of strip subdivision, and leads to much smaller storage required for the structure stiffness and stability matrices. Numerical examples are given, including plates and plate structures subjected to a combination of longitudinal and transverse compression, bending and shear. This study illustrates the power of bubble functions in solving stability problems of plates and plate structures.
