A Security Key Recovery System with Channel Quality Awareness for Smart Grid Applications

Abstract

In this paper, a security key recovery system with channel quality awareness (SKRS-CQA) for smart grid applications has been proposed. Firstly, the proper key recovery agents (KRAs) are determined based on the signal-to-noise ratio (SNR) outage probability. The result of such selection includes the number and the index of selected KRAs. Then, the session key (KS) of a Smart Meter Unit (SMU) will be divided into many different pieces according to the proposed key partitioning algorithm and stored in the selected KRAs for the future key recovery if the data concentrator unit (DCU) has lost the key in unexpected events. The outage probability of SNR, the probability of KRA failure, and the probability of key compromising are also investigated. In addition, a 128-bit AES-GCM encryption algorithm is used in each KRA for authentication and identification mechanisms based on a DLMS/COSEM protocol. As shown in the system performance analysis, the system reliability, the system availability, and the data confidentiality have been improved compared with the conventional scheme. Moreover, a cooperative communication network with an amplify-and-forward relaying protocol and an optimal power allocation has been employed for improving the system reliability. From computer simulation results, it showed that the reliability of the proposed system with a cooperative scheme has been improved significantly.