TSG SA WG3#4, London, 16-18 June 1999-07-09	S3-99195

TSG-T3#6	Tdoc T3-99180
14 June - 16 June, 1999
Miami, Florida

Liaison statement

To:	 SA1, SA3

From:	TSG-T3 (USIM)

Title:	Clarification on the security requirement “USIM-Terminal lock”

For:	Comment

TSG-T3 has studied the requirements on USIM-Terminal Lock presented in chapter 8.2 of the Security Architecture document (33.102 v3.0.0).
Our understanding of this requirement is that two passwords and two user names will have to be stored in the USIM. And three specific procedures have to be supported for enabling, authentication and disabling the USIM-Terminal Lock.

To define the most appropriate solution for the USIM-Terminal lock in the USIM, TSG-T3 would appreciate if TSG-SA1 and TSG-SA3 could provide clarifications on the following points :
-	What are the service requirements from SA1 regarding USIM-Terminal lock?
-	SA1 and SA3 are asked how the terminal is expected to behave when it is locked to one USIM subscription in case there are more than one USIM subscription on the UICC. Should the terminal provide access only to the USIM to which it is locked ?
If the mobile provides access only to the USIM to which it is locked this could be in contradiction with the requirement to have several USIM on the same UICC. Because in this case only USIMs having stored the proper passwords could be selected by the terminal.
It is the current understanding of T3 that the USIM-Terminal lock would work in a similar way to the group identifier as specified in GSM 02.22 and GSM 11.11.