TR 33.856
Study on Security aspects of
Single Radio Voice Continuity
from 5G to UTRAN

V16.1.0 (Wzip) 2019/06 16 p.

full Table of Contents for TR 33.856 Word version: 16.1.0

each clause number in 'red' refers to the equivalent title in the Partial Content

Introduction p. 5

Scope p. 6

References p. 6

Definitions and abbreviations p. 6

3.1	Definitions p. 6
3.2	Abbreviations p. 6

Overview p. 6

Key issues p. 7

Key Issue #1: Achieving backward security of key derivation during SRVCC from 5G to UTRAN CS p. 7

5.1.1	Key issue details p. 7
5.1.2	Security threats p. 7
5.1.3	Potential Security requirements p. 7

Key Issue #2: Security of IMS Emergency Session Handling p. 7

5.2.1	Key issue details p. 7
5.2.2	Security threats p. 7
5.2.3	Potential Security requirements p. 8

Key Issue #3: Protecting the SRVCC capability p. 8

5.3.1	Key issue details p. 8
5.3.2	Security threats p. 8
5.3.3	Potential Security requirements p. 8

Key Issue #4: 5G UE returning from 3G SRVCC to E-UTRA or NR p. 8

5.4.1	Key issue details p. 8
5.4.2	Security threats p. 8
5.4.3	Potential Security requirements p. 8

Solutions p. 9

Solution #1.1: Key derivation during SRVCC from 5G to UTRAN CS without direct interface between AMF and MSC server p. 9

6.1.1	Introduction p. 9
6.1.2	Solution details p. 9
6.1.3	Impacts on existing nodes and functionality p. 10
6.1.4	Evaluation p. 10

Solution #1.2: Key derivation during SRVCC from 5G to UTRAN CS with direct interface between AMF and MSC server p. 10

6.2.1	Introduction p. 10
6.2.2	Solution details p. 11
6.2.3	Impacts on existing nodes and functionality p. 11
6.2.4	Evaluation p. 12

Solution #2: Emergency session in SRVCC from 5G to UTRAN CS p. 12

6.3.1	Introduction p. 12
6.3.2	Solution details p. 12
6.3.3	Impacts on existing nodes and functionality p. 12
6.3.4	Evaluation p. 12

Solution #3: Protecting the SRVCC capability p. 12

6.4.1	Introduction p. 12
6.4.2	Solution details p. 13
6.4.3	Impacts on existing nodes and functionality p. 13
6.4.4	Evaluation p. 13

Solution #4: Return from UTRAN to E-UTRAN or NR p. 13

6.5.1	Introduction p. 13
6.5.2	Solution details p. 13
6.5.3	Impacts on existing nodes and functionality p. 13
6.5.4	Evaluation p. 13

Conclusions p. 14

Change History p. 16