Abstract
Studies of fault tolerant of network can be modeled based on classical graph connectivity. This study is very basic yet it conveys succinct information on the degree of vulnerability of network topology in imbedded systems such as the electrical power system information and communication networks. In this paper, the degree of vulnerability of the North American Electric Reliability Council (NERC) power network to attacks is studied. The degree of vulnerability can be deemed as a measure of the resiliency of the network to attacks launched via cyber means or through physical means. New definition to calculate the Resiliency is proposed. The attacks are simulated either by 'killing' a node that is, by taking a processing element out of service and or by removing links (communication channels) out of service and identifying the overall resiliency of the system. Different cases are carried out. It is anticipated that the results would provide some quantitative measures in terms of the degree of network vulnerability and the resiliency of the network to attacks.