Network Time Protocol Based Time-Varying Encryption System for Smart Grid Meter

Saving energy, reducing costs, and increasing reliability are advantages of smart grid, but only if the safety of the system is guaranteed. To ensure correct operation, communications must be secure. A novel crypto graphic mechanism suitable for smart grid environments, namely the time-varying encryption system, is proposed in this paper. In the Ethernet network, the millisecond level time synchronization among client clocks and the server clock can be reached if they follow the Network Time Protocol (NTP). The time tags and some internal parameters for time synchronization are used for generating the encrypted cipher text at the transmission port. The same sets of time tags and internal parameters are used for recovering the information at the receiving port. Since the time tags and parameters are updated every second, the hacker approach of code-breaking with brute force will fail.