E.1 Introduction

03.203GPPRelease 1999Security related network functionsTS

E.1.1 Scope

This annex specifies the functions needed to provide the security related services and functions specified in GSM 02.56.

E.1.2 References

1 GSM 01.04: "Digital cellular telecommunications system (Phase 2+); Abbreviations and Acronyms".

[2] GSM 02.56: "Digital cellular telecommunications system (Phase 2+); GSM Cordless Telephone System (CTS) Phase 1; Service Description; Stage 1".

[3] GSM 02.09: "Digital cellular telecommunications system(Phase 2+); Security Aspects".

4 GSM 03.56: "Digital cellular telecommunications system (Phase 2+); GSM Cordless Telephone System (CTS), Phase 1; CTS Architecture Description; Stage 2".

5 GSM 11.11: "Digital cellular telecommunications system (Phase 2+); Specification of the Subscriber Identity Module- Mobile Equipment (SIM-ME) interface".

[6] CCITT Recommendation T.50: "International Alphabet No. 5". (ISO 646: 1983, Information processing ‑ ISO 7‑bits coded characters set for information interchange).

7 GSM 03.20: "Digital cellular telecommunications system (Phase 2+); Security related network functions";

8 GSM 04.57: "Digital cellular telecommunications system (Phase 2+); CTS supervising system layer 3 specification ".

E.1.3 Definitions and Abbreviations

E.1.3.1 Definitions

The following list gives definitions which are used in this annex. For additional definitions related to CTS refer to the CTS stage 1 specification GSM 02.56.

Attachment: Attachment is the procedure where a CTS-MS accesses a CTS-FP either for local or over the fixed network communication or signalling. This procedure applies to CTS-MSs that have already been enrolled onto the CTS-FP.

CTS license exempt band: A frequency band that may be allocated by national regulator to CTS usage outside of a GSM license allocated to a GSM operator.

CTS licensed band: A frequency band that can be reserved by the operator for GSM-CTS usage or can be shared with the cellular system.

CTS Local security system: The term CTS local security system is used to describe all security aspects of a CTS-MS/CTS-FP pair.

CTS Operator: This term is used in this annex for any operator performing supervising security tasks in the CTS e.g. control of the CTS subscription or control of the CTS frequency usage. It is not considered here if this is one and the same PLMN operator for all supervising security tasks. However the security functions introduced here shall not restrict the system to be controlled by one specific PLMN operator.

CTS Supervising security system: The term CTS supervising security system is used to describe all security aspects of operation control of the local CTS from the GSM PLMN.

CTS-FP: The CTS Fixed Part consisting of the CTS-FPE and the FP-SIM.

CTS-MS: The CTS Mobile Station consisting of the CTS-ME and the MS-SIM.

Enrolment: The enrolment of a CTS-MS onto a CTS-FP is the procedure where a CTS-MS/CTS-FP pair is established locally and under the control of the CTS operator if license exempt band is used. A CTS-MS can only enrol onto a CTS-FP that has already been initialised.

FP-SIM: The SIM_FP is a GSM Phase 2+ SIM with additional data stored to allow CTS operation. This card is inserted in the CTS-FPE. The FP-SIM is only used in case of licensed band.

IFPSI: The IFPSI is a CTS specific subscriber identity stored in the FP-SIM card.

Initialisation: The initialisation of a CTS-FP is the procedure where the CTS-FP receives the necessary data to provide CTS service.

Local CTS: This term is used to describe all aspects of a CTS-MS/CTS-FP pair as seen from outside (from the GSM PLMN)

MS-SIM: The SIM_MS is a normal GSM Phase 2+ SIM according to GSM 11.11 with additional data stored to allow CTS operation. This card is inserted in the CTS-ME.

Operation data: This term is used as a place holder for any kind of data which is used to control CTS. The definition of this data, if it is not directly related to the CTS security aspects, is defined in other parts of the CTS specifications.

E.1.3.2 Abbreviations

The following list describes the abbreviations and acronyms used in this annex. The GSM abbreviations defined in GSM 01.04 and in the CTS stage 1 specification GSM 02.56 are not included below.

B1 CTS ciphering key generation algorithm

B2 CTS authentication key generation algorithm

B3 CTS authentication algorithm (calculating the signed response of the CTS-FP challenge CH1)

B4 CTS authentication algorithm (calculating the signed response of the CTS-MS challenge CH2)

B5 CTS message authentication algorithm (for the authentication of the CTS-FP by the CTS-SN)

B6 CTS message authentication algorithm (for the authentication of the signature issued by the CTS‑SN)

CH1 CTS random Challenge value of the CTS-FP

CH2 CTS random Challenge value of the CTS-MS

CTS HLR CTS Home Location Register Functional Entity

CTS-FP CTS-Fixed Part

CTS-FPE CTS-Fixed Part Equipment

CTS-ME CTS-Mobile Equipment

CTSMSI CTS Mobile Subscriber Identity related to the x-th CTS-MS enrolled on a CTS-FP

CTS-PIN CTS-Personal Identification Number

CTS-SN

FPAC Fixed part authorisation code (derived from the CTS-PIN)

FP-SIM Fixed Part CTS-Subscriber Identity Module

IFPEI International Fixed Part Equipment Identity

IFPSI International Fixed Part Subscription Identity

Ka CTS authentication key related to the x-th CTS-MS enrolled on a CTS-FP

Kc CTS ciphering key related to the CTS-MS enrolled on a CTS-FP

KiFP CTS subscription authentication key (used for authentication of the CTS-FP by the CTS operator)

KOP Secret key used to validate tokens signed by the operator

MS-SIM Mobile CTS-Subscriber Identity Module

RIFP CTS Random Initial value sent from the CTS-MS to the CTS-FP

RIMS CTS Random Initial value sent from the CTS-FP to the CTS-MS

RK1 CTS Random value of the CTS-MS used for the generation of Kax (not used in the text)

RK2 CTS Random value of the CTS-FP used for the generation of Kax (not used in the text)

SRES1 CTS Signed RESponse of the CTS-FP’s CH1 and the Ka of the CTS-MS

SRES2 CTS Signed RESponse of the CTS-MS’s CH2 and the Ka of the CTS-FP

Tval (in fig E10)

XSRES1 CTS Signed RESponse of the CTS-FP’s CH1 and the Ka of the CTS-FP (to be compared with SRES1)

XSRES2 CTS Signed RESponse of the CTS-MS’s CH2 and the Ka of the CTS-MS (to be compared with SRES2)