A Two-way Interactive Secure Communication Model for Electric Energy Metering Data

INTRODUCTION: As power market reforms deepen, traditional unidirectional protocols (e.g., IEC 102) fail to meet the secure, real-time, and bidirectional data exchange requirements of modern power grids, leaving systems vulnerable to eavesdropping and tampering. OBJECTIVES: To ensure the confidentiality, integrity, and reliability of power data transmission by overcoming the pattern leakage vulnerabilities of traditional encryption, while satisfying the strict real-time and high-frequency demands of large-scale power systems. METHODS: Two schemes are designed: a pure SM4 symmetric encryption scheme for high-frequency data, and an SM2-SM4 hybrid scheme for advanced authentication. To enhance security, a novel ECB-CBC hybrid encryption mode is introduced for SM4.  RESULTS: The proposed ECB-CBC hybrid mode effectively eliminates plaintext redundancy. Its Shannon entropy stabilizes at ~7.99 bits/byte (nearly touching the 8.0 theoretical ideal, vastly improving upon standard ECB's ~3.5 bits/byte). It also achieves an optimal inter-block avalanche effect of ~64 bits per block. The SM2-SM4 hybrid scheme's encryption time is only 15%-20% higher than that of pure SM4. Across 1-16 thread tests, the throughput of both SM4-based schemes grows linearly, outperforming RSA and fully homomorphic encryption (FHE) by several orders of magnitude. CONCLUSION: The proposed ECB-CBC hybrid architecture overcomes standard mode vulnerabilities and achieves the macro-level Strict Avalanche Criterion (SAC), significantly enhancing resistance to network attacks. Compared to traditional asymmetric and homomorphic encryption, the SM4 and SM2-SM4 schemes strike an optimal balance between robust security and computational efficiency for high-concurrency power system applications.