DAC （Discretionary Access Control Policy） is access control based on ownership relations between subject and object, the subject can discretionarily decide on that who, by what methods, can access his owns object. I...DAC （Discretionary Access Control Policy） is access control based on ownership relations between subject and object, the subject can discretionarily decide on that who, by what methods, can access his owns object. In this paper, the system time is looked as a basic secure element. The DAC_T （Discretionary Access Control Policy with Time Character） is presented and formalized. The DAC_T resolves that the subject can discretionarily decide that who, on when, can access his owns objects. And then the DAC_T is implemented on Linux based on GFAC （General Framework for Access Control）, and the algorithm is put forward. Finally, the performance analysis for the DAC T Linux is carried out. It is proved that the DAC T Linux not only can realize time constraints between subject and object but also can still be accepted by us though its performance have been decreased.展开更多
An effective and reliable access control is crucial to a PDM system.This article has discussed the commonly used access control models,analyzed their advantages and disadvantages,and proposed a new Role and Object bas...An effective and reliable access control is crucial to a PDM system.This article has discussed the commonly used access control models,analyzed their advantages and disadvantages,and proposed a new Role and Object based access control model that suits the particular needs of a PDM system.The new model has been implemented in a commercial PDM system,which has demonstrated enhanced flexibility and convenience.展开更多
For the issue of the discretionary access control（DAC） model safety analysis,a logic method is proposed.This method takes the GD model as the classic DAC model and Prolog as the basic language to describe system sta...For the issue of the discretionary access control（DAC） model safety analysis,a logic method is proposed.This method takes the GD model as the classic DAC model and Prolog as the basic language to describe system states and state transfer rules.A general program based on this logic method is proposed for DAC safety analysis,but this program may never be terminal for some safety analysis goal.The safety analysis algorithm is achieved by simplifying the general program according to the property of the DAC model state transfer rules.This safety analysis algorithm is easier to understand and implement than the previous algorithms and its time complexity is O（N＋M＋T）,in which N,M,and T are the numbers of the rights with copy flag,the policies for right transferring,and the policies for right permitting,respectively.展开更多
Access Control(AC)is one of the important technologies of System Security and has been widely studied recently because the traditionary AC technologies can' t meet with the security commands of contemporary imform...Access Control(AC)is one of the important technologies of System Security and has been widely studied recently because the traditionary AC technologies can' t meet with the security commands of contemporary imformation system. As a result,the traditionary AC technologies have been developed and some new technologies have been put forward. This paper makes the necessary classification for the more-than-ten-year research results of the AC technology,together with the analysis and predication for the development trend of the AC technology in the future.展开更多
基金Supported by the National 863 Broad Band VPN Project (No.863-104-03-01)
文摘DAC （Discretionary Access Control Policy） is access control based on ownership relations between subject and object, the subject can discretionarily decide on that who, by what methods, can access his owns object. In this paper, the system time is looked as a basic secure element. The DAC_T （Discretionary Access Control Policy with Time Character） is presented and formalized. The DAC_T resolves that the subject can discretionarily decide that who, on when, can access his owns objects. And then the DAC_T is implemented on Linux based on GFAC （General Framework for Access Control）, and the algorithm is put forward. Finally, the performance analysis for the DAC T Linux is carried out. It is proved that the DAC T Linux not only can realize time constraints between subject and object but also can still be accepted by us though its performance have been decreased.
文摘An effective and reliable access control is crucial to a PDM system.This article has discussed the commonly used access control models,analyzed their advantages and disadvantages,and proposed a new Role and Object based access control model that suits the particular needs of a PDM system.The new model has been implemented in a commercial PDM system,which has demonstrated enhanced flexibility and convenience.
基金Supported by the National High Technology Research and Development Program of China (863 Program) (2007AA01Z471)
文摘For the issue of the discretionary access control（DAC） model safety analysis,a logic method is proposed.This method takes the GD model as the classic DAC model and Prolog as the basic language to describe system states and state transfer rules.A general program based on this logic method is proposed for DAC safety analysis,but this program may never be terminal for some safety analysis goal.The safety analysis algorithm is achieved by simplifying the general program according to the property of the DAC model state transfer rules.This safety analysis algorithm is easier to understand and implement than the previous algorithms and its time complexity is O（N＋M＋T）,in which N,M,and T are the numbers of the rights with copy flag,the policies for right transferring,and the policies for right permitting,respectively.
文摘Access Control(AC)is one of the important technologies of System Security and has been widely studied recently because the traditionary AC technologies can' t meet with the security commands of contemporary imformation system. As a result,the traditionary AC technologies have been developed and some new technologies have been put forward. This paper makes the necessary classification for the more-than-ten-year research results of the AC technology,together with the analysis and predication for the development trend of the AC technology in the future.
