This part of IEC 62351 specifies procedures, protocol extensions, and algorithms to facilitate securing ISO 9506 - Manufacturing Message Specification (MMS) based applications. It is intended that this technical specification be referenced as a normative part of other IEC TC 57 standards that have the need for using MMS in a secure manner. This technical specification represents a set of mandatory and optional security specifications to be implemented for applications when using ISO/IEC 9506 (Manufacturing Automation Specification). NOTE Within the scope of IEC TC 57, there are two identified standards that may be impacted: IEC 61850-8-1 and IEC 60870-6. This specification contains a set of specifications that are to be used by referencing standards in order to secure information transferred when using MMS. The recommendations are based upon specific communication profile protocols used in order to convey MMS information. IEC 61850-8-1 and IEC 60870-6 make use of MMS in a 7-layer connection-oriented mechanism. Each of these standards is used over either the OSI or TCP profiles.