Abstract: To solve the security problem of data interception, forgery and tampering in the process of the smart grid communication, the dynamic key-based lightweight data encryption was improved. A scheme of data integrity authentication was proposed based on the analysis of the communication characteristics of the smart grid. The initial key was embedded in the device. The non-retransmission packets were used to synchronously update the two-party key, the exclusive-or algorithm was used to complete the data symmetric encryption and decryption. In addition, the key and the message are used as the input of the Hash algorithm, and the Hash value was used as the message digest to complete data integrity authentication. Libmodbus open source library was used to simulate the communication between master and slave devices. Experiments show that the synchronization and accuracy of key update are ensured, the key self-organization and management are realized, the data transmission is completed correctly, and the resource consumption is obviously superior to the existing algorithm.

Key words: smart power grid, data encryption, data authentication, dynamic key, symmetric encryption