IEC 62055-41:2018 specifies the application layer protocol of the standard transfer specification (STS) used for transferring units of credit and other management information from a point of sale (POS) system to an STS-compliant payment meter in a one-way token carrier system. It is primarily intended for application with electricity payment meters without a tariff employing energy-based tokens, but may also have application with currency-based token systems and for services other than electricity. It is intended for use by manufacturers of payment meters that have to accept tokens that comply with the STS and also by manufacturers of POS systems that have to produce STS-compliant tokens and is to be read in conjunction with IEC 62055-5x series. This third edition cancels and replaces the second edition of IEC 62055-41, issued in 2014. It constitutes a technical revision. The main technical changes with regard to the previous edition are as follows:
- currency transfer tokens for electricity, water, gas and time metering;
- finer resolution for gas and time credit transfer;
- common code PAN for 2 and 4 digit manufacturer codes;
- reserved MfrCode values for certification and testing purposes;
- provision for DLMS/COSEM as a virtual token carrier type;
- addition of DKGA04, an advanced key derivation function from 160-bit VendingKey;
- withdrawal of DES for EA09 and TDES for DKGA03 cryptographic algorithms, but DES for DKGA02 remains in use;
- addition of MISTY1 cryptographic algorithm using a 128-bit DecoderKey with supporting key change tokens;
- transfer of SGC values to the meter via key change tokens;
- revision of the test/display token requirements;
- revision of the KMS to reflect current best practice;
- revision of the TID roll over management guidelines;
- definition of BaseDate is referenced to Coordinated Universal Time;
- some clarifications and additional examples have been added.