Section: B.2.1.2.1 EAP TLS without subscription identifier privacy
Content: For EAP TLS, if the operator determines to not provide subscription identifier privacy for the UE in TLS layer (e.g., in TLS 1.2 without privacy option), the subscription identifier protection in NAS layer, i.e., in Step 1 of Figure B.2.1-1, becomes ineffective privacy-wise. Therefore, the operator may just choose that UE uses "null-scheme" for calculation of SUCI which is sent in NAS layer. However, the operator may anyway use other than null-schemes (e.g., one of ECIES schemes) for simplification of having single scheme for all UEs in NAS layer even though privacy is not enhanced in this particular case. The operator could also determine not to provide subscription identifier privacy for the UE in NAS layer even though the TLS layer inherently provides subscription identifier privacy (e.g., in TLS 1.3). In such case, the operator may just choose that UE uses "null-scheme" for calculation of SUCI which is sent in NAS layer.