Department Publications

This thesis is about issues related to the security of electric substations automated by IEC61850, an Ethernet (IEEE 802.3) based protocol. It is about a comprehen sive security analysis and development of a viable method of auditing the security of this protocol. The security analysis focuses on the possible threats to an electric substation based on the possible motives of an attacker. Existing methods and met rics for assessing the security of computer networks are explored and examined for suitability of use with IEC61850. Existing methods and metrics focus on conven tional computers used in computer networks which are fundamentally different from Intelligent Electronic Devices (IED’s) of substations in terms of technical composition and functionality. Hence, there is a need to develop a new method of assessing the security of such devices. The security analysis is then used to derive a new metric scheme to …

This paper details the use of decision fusion from the outputs of different types of classifiers used for analyzing network traffic to detect masquerading within an IEC61850 automated substation. Data on network traffic is collected under simulated scenarios of a genuine user casually browsing data and an attacker rapidly downloading restricted data. The logarithm of the time difference between two successive packets is calculated and the histogram of this is used for classification using support vector machines and nearest neighbor classifiers. Decision fusion of the outputs of the best classifiers is done using evidence theory and possibility theory in order to reduce the number of input data and increase the reliability.

This paper presents a case study of the application of security metrics to a computer network. A detailed survey is conducted on existing security metric schemes. The Mean Time to Compromise (MTTC) metric and VEA-bility metric are selected for this study. The input data for both metrics are obtained from a network security tool. The results are used to determine the security level of the network using the two metrics. The feasibility and convenience of using both metrics are then compared.

MAGI array is a very popular antenna for ITIE/UHF applications due to its simple construction. It is extensively used in television and FM radio reception. However, design of MAGI arrays to meet a given set of specifications is a very difficult task. This paper presents a genetic algorithm based design technique for MAGI arrays for receiving applications