Segurança cibernética com hardware reconfigurável em subestações de energia elétrica utilizando o padrão IEC 61850
Data
2017-11-15
Autores
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Biblioteca Digital de Teses e Dissertações da USP
Universidade de São Paulo
Escola de Engenharia de São Carlos
Universidade de São Paulo
Escola de Engenharia de São Carlos
Resumo
Descrição
Com a tecnologia digital, as redes de comunicação têm sido de fundamental importância para o bom funcionamento das subestações de energia elétrica. Criado em 2002, o padrão IEC 61850 busca harmonizar a diversidade de equipamentos e fabricantes, e possibilitar a integração de dados para que o máximo de benefícios possa ser extraído. Nesse contexto, o protocolo GOOSE (Generic Object Oriented Substation Event), pertinente ao padrão IEC 61850, é um datagrama multicast concebido para funcionar na rede local ou de longa distância que interliga as subestações de energia elétrica. Nos ambientes de longa distância, o tráfego de dentro para fora, e vice-versa, deveria passar por um firewall. Porém, a tecnologia de firewall atual não é capaz de inspecionar as mensagens GOOSE reais ou originadas a partir de um ataque, e afeta o tempo de transferência das mesmas, que, no enlace de comunicação, não deve exceder 5ms. Dessa forma, o objetivo deste trabalho é desenvolver um firewall em hardware reconfigurável, por meio da plataforma NetFPGA, de modo que o incremento no tempo de propagação de uma mensagem GOOSE, Tipo 1A (Trip), ao transpor o dispositivo de segurança, não ultrapasse 20% do tempo total destinado ao enlace de comunicação. Por ter a capacidade de ser um acelerador, construído por meio de hardware reconfigurável FPGA (Field Programmable Gate Array), a NetFPGA conduz enlaces Gigabit, e torna possível examinar e estabelecer regras iniciais de autorização ou negação para o tráfego de mensagens GOOSE, manipulando os campos do quadro ISO/IEC 8802-3. O incremento no tempo máximo de propagação de uma mensagem com 1518 bytes foi de 77,39 μs, com 77,38 μs de tempo médio. Um algoritmo de criptografia e outro de autenticação também foram testados e mensagens falsas não conseguiram transpor o firewall. No momento atual da pesquisa, concluiu-se que o firewall em NetFPGA, pertinente ao conjunto de recursos de hardware e software destinados a garantir a segurança de uma rede, é capaz de rejeitar mensagens GOOSE falsas e fornecer segurança aos dispositivos ativos de uma subestação, sem atrasos adicionais superiores a 1ms.
With the digital technology, the communication networks have been of fundamental importance for the good performance of power substations. Created in 2002, the IEC 61850 standard seeks for harmonization of the different equipment and manufacturers, enabling the integration of data for maximum performance. In this context, the GOOSE (Generic Object Oriented Substation Event) message, concerning the IEC 61850 standard, is a multicast datagram, designed to operate in LAN or WAN that connects power substations. In the long-distance environment, the propagation time in the communication link must not exceed 5ms. The current firewall technology is not able to differ true GOOSE messages from the ones originated from an attack, and it affects the transfer time of messages. The objective of this research is to develop a reconfigurable firewall hardware, using the NetFPGA platform, so that the increase in propagation time of a GOOSE message, Type 1A (Trip), does not exceed 20% of the total time allocated to the link communication. Due to the ability of NetFPGA of being an accelerator, and having been built by using reconfigurable FPGA (Field Programmable Gate Array) leading to Gigabit links, it was possible to examine and establish initial rules of authorization or denial of GOOSE messages by manipulating some of the fields from the table ISO/IEC 8802-3. The increase in the maximum propagation time of a message of 1518 bytes was 77.39 μs, with the average of 77.38 μs. Fake messages failed to cross the firewall. Results from a process of authentication and encryption were also presented. At the present study, it has been concluded that the firewall using NetFPGA, concerning the hardware and software in order to ensure the security of a network, is able to reject false GOOSE messages and provide security to devices of a power substation without time increments greater than 1ms.
With the digital technology, the communication networks have been of fundamental importance for the good performance of power substations. Created in 2002, the IEC 61850 standard seeks for harmonization of the different equipment and manufacturers, enabling the integration of data for maximum performance. In this context, the GOOSE (Generic Object Oriented Substation Event) message, concerning the IEC 61850 standard, is a multicast datagram, designed to operate in LAN or WAN that connects power substations. In the long-distance environment, the propagation time in the communication link must not exceed 5ms. The current firewall technology is not able to differ true GOOSE messages from the ones originated from an attack, and it affects the transfer time of messages. The objective of this research is to develop a reconfigurable firewall hardware, using the NetFPGA platform, so that the increase in propagation time of a GOOSE message, Type 1A (Trip), does not exceed 20% of the total time allocated to the link communication. Due to the ability of NetFPGA of being an accelerator, and having been built by using reconfigurable FPGA (Field Programmable Gate Array) leading to Gigabit links, it was possible to examine and establish initial rules of authorization or denial of GOOSE messages by manipulating some of the fields from the table ISO/IEC 8802-3. The increase in the maximum propagation time of a message of 1518 bytes was 77.39 μs, with the average of 77.38 μs. Fake messages failed to cross the firewall. Results from a process of authentication and encryption were also presented. At the present study, it has been concluded that the firewall using NetFPGA, concerning the hardware and software in order to ensure the security of a network, is able to reject false GOOSE messages and provide security to devices of a power substation without time increments greater than 1ms.
Palavras-chave
Firewall, Redes de comunicação, NetFPGA, IEC 62351, Segurança cibernética, IEC 61850, GOOSE, Hardware Reconfigurável, IEC 61850, Reconfigurable hardware, Network communications, Cyber security, NetFPGA, Firewall, GOOSE, IEC 62351