Adapting the Pretty Good Privacy Security Style to Power System Distributed Network Protocol

Power system modernization with increasing operation automation and integration results in growing computer network access. This facilitates cyber-attackers' capabilities to assume control over power system operations that could cause serious blackouts. Security therefore becomes a critical issue for DNP3, a commonly used protocol for power system communications. This paper proposes cyber-security based on Pretty Good Privacy (PGP) for DNP3 to strengthen computer network security. This PGP-based cyber-security provides authentication capabilities using public key cryptography, with enhanced performance using symmetric keys for most of the encryption. This paper provides a symmetric cipher key exchange mechanism using PGP-based cyber-security to further enhance the power system security. The proposed PGP-based cyber-security is implemented as a pseudo-layer below the DNP3 data-link layer to minimize any impact on the DNP3 specifications and the operations of original DNP3 devices. This PGP-based cyber-security provides confidentiality, identity authentication, transmission content authentication, and nonrepudiation