This part of IEC 62351, which is a technical specification, describes test cases of data andcommunication security for telecontrol equipment, Substation Automation Systems [SAS] andtelecontrol systems, including front-end functions of SCADA.The goal of this document is to enable interoperability by providing a standard method of testing protocol implementations to verify that a device fulfils the requirement of IEC 62351-3. Note that conformity to IEC 62351-3 does not guarantee interoperability between devices using different implementations. It is expected that using this specification during testing will minimize the risk of non-interoperability. A basic condition for this interoperability is a passed conformance test of both devices.