KNEMAG:Key Node Estimation Mechanism Based on Attack Graph for IoT Security

With the rapid development and widespread application of the IoT,the at-tacks against IoT vulnerabilities have become more complex and diverse.Most of the previous research focused on node vulnerability and its risk analysis.There is little information available about the importance of the location of the node in the system.Therefore,an estimation mechanism is proposed to assess the key node of the IoT system.The estimation of the key node includes two parts:one is the utilization relationship between nodes,and the other is the impact on the system after the node is conquered.We use the node importance value and the node risk value to quantify these two parts.First,the node importance value is calculated by considering the attack path that pass through the node and the probability that the attacker will abandon the attack.Second,in addition to node vulnerabilities and the consequences of being attacked,two quantitative indicators are proposed to comprehensively assess the impact of nodes on the system security,and the node risk value is calculated based on the grey correlation analysis method.Third,the key node in the IoT system could be obtained by integrating the node importance value and risk value.Finally,the simulation experiment result shows that the presented method could find the key node of the system quickly and accurately.

Constructing the three-qudit unextendible product bases with strong nonlocality

Unextendible product bases(UPBs)are interesting members of a family of orthogonal product bases.Here,we investigate the construction of 3-qudit UPBs with strong nonlocality.First,a UPB set in C^(3)■C^(3)■C^(3)of size 19 is presented based on the shift UPBs.By mapping the system to a Rubik’s cube,we provide a general method of constructing UPBs in C^(d)■C^(d)■C^(d)of size(d-1)^(3)+2d+5,whose corresponding Rubik’s cube is composed of four parts.Second,for the more general case where the dimensions of parties are different,we extend the classical tile structure to the 3-qudit system and propose the tri-tile structure.By means of this structure,a C^(4)■C^(4)■C^(5)system of size 38 is obtained based on a C^(3)■C^(3)■C^(4)system of size 19.Then,we generalize this approach to the C^(d1)■C^(d2)■C^(d3)system which also consists of four parts.Our research provides a positive answer to the open question raised in by Halder et al.[Phys.Rev.Lett.122040403(2019)],indicating that there do exist UPBs that can exhibit strong quantum nonlocality without entanglement.