E.2 General

3GPP43.020Release 17Security related network functionsTS

In 3GPP TS 42.056 the CTS service is introduced and security service requirements are listed. Based on this, the CTS security system can be seen as a set of two subsystems, the CTS local security system and the CTS supervising security system.

The local security system deals with aspects of CTS-MS/CTS-FP pairs. It is related to security aspects of the CTS user. The different CTS local security services, functions and procedures that are listed in 3GPP TS 42.056 are grouped as follows:

– MS subscriber identity confidentiality;

– identity authentication (including the MS subscriber identity – and the FP subscriber identity authentication);

– confidentiality of user and signalling information between CTS-MS and CTS-FP.

These functions are part of the following procedures:

– local part of the CTS enrolment/de-enrolment procedures;

– access procedure of a CTS-MS/CTS-FP pair.

When licensed band is used, the supervising security system deals with aspects of network security. It is related to security aspects of the CTS operator. The different CTS supervising security services, functions and procedures that are listed in 3GPP TS 42.056 are grouped as follow:

– identity authentication with the CTS operator (including the FP subscriber authentication and if required the MS subscriber authentication with the GSM operator);

– secure operation control;

– subscription Control;

– equipment checking (IMEI, IFPEI).

These functions are part of the following procedures:

– CTS system initialisation/de-initialisation procedures;

– CTS supervising security part of the CTS enrolment procedure;

– CTS-FP/CTS-SN Access procedure;

General comments on the figures in this annex:

– in the figures below, signalling exchanges are referred by functional names;

– signalling refers to exchange of information. This shall not imply any implementation of information elements and messages at this stage of the CTS specification.

– addressing fields are not given; all information relates to the signalling layer.