Abstract: Frequent power outages plague underdeveloped regions such as Africa, accompanied by urgent demands for multi-scenario metering, tariff deduction, and electricity theft prevention. This paper proposes a full-process secure multi-account metering and tariff deduction scheme based on system-on-chip (SOC) microchips. Taking SOC chips integrating metering modules and hardware encryption engines as the core terminal carrier, a lightweight elliptic curve cryptography security architecture is established: the ECDH key exchange protocol is adopted to securely negotiate session keys between terminals and the master station, eliminating risks of plaintext key transmission; the ECDSA digital signature algorithm is deployed to perform identity authentication and integrity verification on STS recharge commands and multi-account tariff deduction transaction data, fundamentally preventing forged commands and data tampering. Meanwhile, leveraging the hardware-level security protection capabilities of SOC chips, secure storage of metering data and cryptographic keys is realized to defend against unauthorized debugging and channel attacks. Test results demonstrate that the proposed scheme not only supports multi-account metering and tariff deduction, but also delivers markedly improved communication anti-attack performance as well as metering reliability and stability.