Codificação de rede como alternativa para aumentar a segurança na camada física em smart grids

Abstract

Smart grids represent future of electrical power systems . These kind of networks must be robust to load fluctuations as well as have smart monitoring and intelligent management in real-time fashion . Based on the aforementioned needs, many authors propose the use of wireless communication systems in order to meet these demands, due to their efficient tradeoff between low-cost and high-seed when compared to wired connections such as optical fibens or metallic cables, and, in addition, they are flexible to topology changes and do not have constrainsts in terms of standards and devices, the opposite for example to the case of PLC(Power Line Comminications) .Due to the broadcast nature of the wireless medium , security is onde of the critical issues in smart grids since the occurrence of attacks can lead to load fluctuations and blackouts in the electrical system, or generate secrecy problems, in the situation where passive eaversdroppers intercept messages in the network aiming to obtain some kind of benefit . This second case of passive attacks will be addressed in the work. In addition to classical cryptography strategies commonly used to increase the security in communications systems another area which has been studied by the scientific community is the physical-layer security, which is based on the Shannon’s information theory. In this work, we use the network coding technique as tool to increase the physical-layer in a mulple access wireless network, where two users have independent information to transmit to a common destination, in the presence of an eavesdropper. By using the secrecy outage probability as the metric, we show through theoretic and numerical results that the network security can be increased through the use of network coding when compared to the transmission and traditional cooperative techniques.