Key management for advanced power distribution system using EPON

Advanced distribution operation is an increasingly important function for smart grid, and a reliable communication network constitutes the core of the advanced distribution automation system. Ethernet Passive Optical Network (EPON) is regarded as a promising fiber-based communication technique for advanced distribution automation because it is not only high-speed, cost-effective but also scalable. However, EPON has very specific security requirements, due to its broadcasting character of transmission medium in the downstream direction. Group key management plays an essential role for the guarantee of data confidentiality and integrity. This paper proposes to encrypt the broadcasting information transmitted in the EPON using the encryption key. To reduce the size of rekeying messages and achieve the sufficient scalability, a hybrid key management model is presented, where a Logical Key Hierarchy (LKH) with decentralized architecture is employed.