As a new computing mode,cloud computing can provide users with virtualized and scalable web services,which faced with serious security challenges,however.Access control is one of the most important measures to ensure ...As a new computing mode,cloud computing can provide users with virtualized and scalable web services,which faced with serious security challenges,however.Access control is one of the most important measures to ensure the security of cloud computing.But applying traditional access control model into the Cloud directly could not solve the uncertainty and vulnerability caused by the open conditions of cloud computing.In cloud computing environment,only when the security and reliability of both interaction parties are ensured,data security can be effectively guaranteed during interactions between users and the Cloud.Therefore,building a mutual trust relationship between users and cloud platform is the key to implement new kinds of access control method in cloud computing environment.Combining with Trust Management(TM),a mutual trust based access control(MTBAC) model is proposed in this paper.MTBAC model take both user's behavior trust and cloud services node's credibility into consideration.Trust relationships between users and cloud service nodes are established by mutual trust mechanism.Security problems of access control are solved by implementing MTBAC model into cloud computing environment.Simulation experiments show that MTBAC model can guarantee the interaction between users and cloud service nodes.展开更多
In the last decade,cognitive radio(CR) has emerged as a major next generation wireless networking technology,which is the most promising candidate solution to solve the spectrum scarcity and improve the spectrum utili...In the last decade,cognitive radio(CR) has emerged as a major next generation wireless networking technology,which is the most promising candidate solution to solve the spectrum scarcity and improve the spectrum utilization.However,there exist enormous challenges for the open and random access environment of CRNs,where the unlicensed secondary users(SUs) can use the channels that are not currently used by the licensed primary users(PUs) via spectrum-sensing technology.Because of this access method,some malicious users may access the cognitive network arbitrarily and launch some special attacks,such as primary user emulation attack,falsifying data or denial of service attack,which will cause serious damage to the cognitive radio network.In addition to the specifi c security threats of cognitive network,CRNs also face up to the conventional security threats,such as eavesdropping,tampering,imitation,forgery,and noncooperation etc..Hence,Cognitive radio networks have much more risks than traditional wireless networks with its special network model.In this paper,we considered the security threats from passive and active attacks.Firstly,the PHY layer security is presented in the view of passive attacks,and it is a compelling idea of using the physical properties of the radio channel to help provide secure wireless communications.Moreover,malicious user detection is introduced in the view of active attacks by means of the signal detection techniques to decrease the interference and the probabilities of false alarm and missed detection.Finally,we discuss the general countermeasures of security threats in three phases.In particular,we discuss the far reaching effect of defensive strategy against attacks in CRNs.展开更多
Currently, under the cloud service architecture, the increasing importance of network security and security issues are still emerging. With the rapid development of the network platform, it is connected to the number ...Currently, under the cloud service architecture, the increasing importance of network security and security issues are still emerging. With the rapid development of the network platform, it is connected to the number and size of the trusted computing environment for all kinds of applications that are rapidly expanding, ever-changing network health, network time being emergencies, assault, failure, threat of disaster, its safety, survivability and availability of face serious challenges. Although TNC Working Group made safe and reliable framework from the network access layer, it is not at the level of user access, system access levels and further given the level of situational awareness and effective solutions.展开更多
基金ACKNOWLEDGEMENT This paper is supported by the Opening Project of State Key Laboratory for Novel Software Technology of Nanjing University, China （Grant No.KFKT2012B25） and National Science Foundation of China （Grant No.61303263）.
文摘As a new computing mode,cloud computing can provide users with virtualized and scalable web services,which faced with serious security challenges,however.Access control is one of the most important measures to ensure the security of cloud computing.But applying traditional access control model into the Cloud directly could not solve the uncertainty and vulnerability caused by the open conditions of cloud computing.In cloud computing environment,only when the security and reliability of both interaction parties are ensured,data security can be effectively guaranteed during interactions between users and the Cloud.Therefore,building a mutual trust relationship between users and cloud platform is the key to implement new kinds of access control method in cloud computing environment.Combining with Trust Management(TM),a mutual trust based access control(MTBAC) model is proposed in this paper.MTBAC model take both user's behavior trust and cloud services node's credibility into consideration.Trust relationships between users and cloud service nodes are established by mutual trust mechanism.Security problems of access control are solved by implementing MTBAC model into cloud computing environment.Simulation experiments show that MTBAC model can guarantee the interaction between users and cloud service nodes.
基金supported in part by the National Natural Science Foundation of China(61227801,61121001,61201152,and 61421061)the Program for New Century Excellent Talents in University(NCET-01-0259)the Fundamental Research Funds for the Central Universities(2013RC0106)
文摘In the last decade,cognitive radio(CR) has emerged as a major next generation wireless networking technology,which is the most promising candidate solution to solve the spectrum scarcity and improve the spectrum utilization.However,there exist enormous challenges for the open and random access environment of CRNs,where the unlicensed secondary users(SUs) can use the channels that are not currently used by the licensed primary users(PUs) via spectrum-sensing technology.Because of this access method,some malicious users may access the cognitive network arbitrarily and launch some special attacks,such as primary user emulation attack,falsifying data or denial of service attack,which will cause serious damage to the cognitive radio network.In addition to the specifi c security threats of cognitive network,CRNs also face up to the conventional security threats,such as eavesdropping,tampering,imitation,forgery,and noncooperation etc..Hence,Cognitive radio networks have much more risks than traditional wireless networks with its special network model.In this paper,we considered the security threats from passive and active attacks.Firstly,the PHY layer security is presented in the view of passive attacks,and it is a compelling idea of using the physical properties of the radio channel to help provide secure wireless communications.Moreover,malicious user detection is introduced in the view of active attacks by means of the signal detection techniques to decrease the interference and the probabilities of false alarm and missed detection.Finally,we discuss the general countermeasures of security threats in three phases.In particular,we discuss the far reaching effect of defensive strategy against attacks in CRNs.
文摘Currently, under the cloud service architecture, the increasing importance of network security and security issues are still emerging. With the rapid development of the network platform, it is connected to the number and size of the trusted computing environment for all kinds of applications that are rapidly expanding, ever-changing network health, network time being emergencies, assault, failure, threat of disaster, its safety, survivability and availability of face serious challenges. Although TNC Working Group made safe and reliable framework from the network access layer, it is not at the level of user access, system access levels and further given the level of situational awareness and effective solutions.
