This European Telecommunication Standard (ETS) specifies the interface between the DECT Authentication Module (DAM) and the Portable Equipment (PE) for use in the Digital European Cordless Telecommunications (DECT) system as well as those aspects of the internal organisation of the DAM which are related to this use. This is to ensure interoperability between a DAM and a PE independently of the respective manufacturers and operators. The concept of a split of the Portable Part (PP) into a DAM@ a type of Integrated Circuit (IC) card@ and a PE is described in ETS 300 175-7 [4]. Where equivalent functions are provided in both the PE and the DAM@ the DAM functions take precedence over the functions implemented in the PE. This ETS specifies: - the requirements for the physical characteristics of the DAM@ the electronic signals and the transmission protocols; - the model which shall be used as a basis for the design of the logical structure of the DAM; - the security services and facilities; - the DAM functions which may be requested by the PE over the interface; - the commands; - the contents of the files required for the DECT application; - the application protocol. This ETS does not specify any aspects related to the administrative management phase. Any internal technical realization of either the DAM or the PE are only specified where these reflect over the interface. This ETS does not specify any of the security algorithms which may be used.