Prepaid Power Meter can be divided into two types: medium and non-medium, and the most representative Prepaid Power Meter with medium is IC card meter; Medialess Prepaid Power Meter are recharged through communication encryption, and STS encryption is still the most secure in the current market from the perspective of encryption reliability. Because the safety of Prepaid Power Meter in STS standards is extremely high, they have been recognized by the global industry and become the standard requirements for prepaid electricity meters in African countries with urgent prepaid needs