SEDE: State estimation-based dynamic encryption scheme for smart grid communication

The vision of smart grid relies heavily on the communication technologies as they provide a desirable infrastructure for real-time measurement, transmission, decision and control. But various attacks such as eavesdropping, information tampering and malicious control command injection that are hampering the communication in Internet, would impose great threat on the security and stability of smart grids. In this paper, a State Estimation-based Dynamic Encryption (SEDE) scheme is proposed to secure the communication in smart grid. Several states of power system are employed as the common secrets to generate a symmetric key at both sides, which are measured on the terminals and calculated on the control center using state estimation. The advantages of SEDE are 1) the common secrets, used to generate symmetric key, are never exchanged in the network due to the state estimation, that observably improves the security of SEDE; 2) the measurement and state estimation are the essential functions on the terminals and control center in power system; 3) the functions, applied to encrypt and decrypt data, are simple and easy-implemented, such as XOR, Hash, rounding, etc. Thus, SEDE is considered as an inherent, light-weight and high-security encryption scheme for smart gird. In the experiments, SEDE is simulated on a 4-bus power system to demonstrate the process of state estimation, key generation and error correction.