Content for TS 43.020 Word version: 18.0.0

0 Scope p. 10

This Technical Specification specifies the network functions needed to provide the security related service and functions specified in TS 42.009.

This specification does not address the cryptological algorithms that are needed to provide different security related features. This topic is addressed in Annex C. Wherever a cryptological algorithm or mechanism is needed, this is signalled with a reference to Annex C. The references refers only to functionalities, and some algorithms may be identical or use common hardware.

0.1 References p. 10

The following documents contain provisions which, through reference in this text, constitute provisions of the present document.

References are either specific (identified by date of publication, edition number, version number, etc.) or non specific.
For a specific reference, subsequent revisions do not apply.
For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.

[1]

TS 21.905: "Vocabulary for 3GPP Specifications".

[2]

TS 41.061: "GPRS ciphering algorithm requirements".

[3] Void

[4]

TS 42.009: "Security aspects".

[5]

TS 42.017: "Subscriber Identity Modules (SIM) Functional characteristics".

[6]

TS 42.056: "GSM Cordless Telephone System (CTS) Phase 1; Service Description; Stage 1".

[7]

TS 22.060: "General Packet Radio Service (GPRS); Service description; Stage 1".

[8]

TS 23.003: "Numbering, addressing and identification".

[9]

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

[10]

TS 23.060: "Service description; Stage 2".

[11]

TS 24.008: "Mobile radio interface layer 3 specification".

[12] Void

[13]

TS 45.001: "Physical layer on the radio path; General description".

[14]

TS 45.002: "Multiplexing and multiple access on the radio path".

[15]

TS 45.003: "Channel coding".

[16]

TS 29.002: "Mobile Application Part (MAP) specification".

[17]

TS 51.011: "Specification of the Subscriber Identity Module- Mobile Equipment (SIM-ME) interface".

[18]

TS 33.102: "Technical Specification Group Services and System Aspects; 3G Security; Security architecture ".

[19]

TS 24.301: "Technical Specification Group Core Network and Terminals; Non-Access-Stratum (NAS) protocol for Evolved Packet System (EPS)".

[20]

TS 44.064: "Technical Specification Group Core Network and Terminals; Mobile Station - Serving GPRS Support Node (MS-SGSN); Logical Link Control (LLC) layer specification".

[21]

TS 55.226: " Technical Specification Group Services and System Aspects; 3G Security; Specification of the A5/4 encryption algorithms for GSM and ECSD, and the GEA4 encryption algorithm for GPRS".

[22]

TS 33.220: "Generic Authentication Architecture (GAA); Generic Bootstrapping Architecture (GBA)".

[23] Void

[24]

TS 33.102: "3G security; Security architecture".

[25]

TS 55.251: "Specification of the GEA5 encryption and GIA5 integrity algorithms for GPRS; GEA5 and GIA5 algorithm specification".

[26]

TS 55.241: "Specification of the GIA4 integrity algorithm for GPRS; GIA4 specification".

0.2 Abbreviations p. 11

Abbreviations used in this specification are listed in TS 21.905.

Specific abbreviations used in Annex A are listed in clause A.3.

Specific CTS related abbreviations used in Annex E are listed in clause E.1.3.

Specific VCGS and VBS related abbreviations used in Annex F are listed in clause F.1.3.

Throughout this specification, the abbreviation Kc128 is used to indicate a 128-bit ciphering key as derived by UMTS AKA [18]. The abbreviation Kc128 is only used where it matters that the ciphering key is 128 bits long; the abbreviation Kc is used in all other places.

1 General p. 11

The different security related services and functions that are listed in TS 42.009 are grouped as follows:

Subscriber identity confidentiality;
Subscriber identity authentication;
Signalling information element and connectionless user data confidentiality and data confidentiality for physical connections (ciphering).

It shall be possible to introduce new authentication and ciphering algorithms during the systems lifetime. The fixed network may support more than one authentication and ciphering algorithm.

The security procedures include mechanisms to enable recovery in event of signalling failures. These recovery procedures are designed to minimize the risk of a breach in the security of the system.

General on Figures in this specification:

In the Figures below, signalling exchanges are referred to by functional names. The exact messages and message types are specified in TS 24.008 and TS 29.002.
No assumptions are made for function splitting between MSC (Mobile Switching Centre), VLR (Visitor Location Register) and BSS (Base Station System). Signalling is described directly between MS and the local network (i.e. BSS, MSC and VLR denoted in the Figures by BSS/MSC/VLR). The splitting in annex A is given only for illustrative purposes.
Addressing fields are not given; all information relates to the signalling layer. The TMSI allows addressing schemes without IMSI, but the actual implementation is specified in the GSM 04-series.
The term HPLMN in the Figures below is used as a general term which should be understood as HLR (Home Location Register) or AuC (Authentication Centre).
What is put in a box is not part of the described procedure but it is relevant to the understanding of the figure.