prEN IEC 62055-42:2021

The scope of this standard is the specification of a token generation mechanism and token structure for smart prepayment functionality in markets where IEC 62055-41 compliant systems are not used and where a different security mechanism is required by project-specific or national requirements. This standard specifies token structure, authentication and an anti-replay mechanism, token operating model, and protocol. This standard is informed by the STS Association key management services, and by the key management mechanisms used within the DLMS/COSEM security model within IEC 62056-6-2. Normative reference is made to the international STS token standards (IEC 62055-41, -51, -52) for payment metering systems, and interworking has been considered where appropriate in terms of token carrier ranges in the decimal domain. It should be noted at this point that IEC 62055-41 tokens and those described in this standard are not interoperable, however their domains are designed to be mutually exclusive to ensure the two kinds of tokens do not interfere with each other. Metering application processing and functionality, HAN interface commands and attributes, WAN interface commands and attributes are outside the scope of this standard; however, reference is made to other standards in this regard. The mechanism for auditing and retrieving data from the meter relating to tariffication, meter readings, profile data and other legal metrology information is outside the scope of this standard; however, this needs to be defined as part of any overall metering solution. Such interfaces for retrieving data from a meter may be defined using suitable protocols such as DLMS/COSEM as defined in the IEC 62056 series.