Question: What type of encryption is sufficient for the user plane and signalling between the UE and TNGF when using trusted non-3GPP access to the 5G Core network?
Option 1: AES encryption
Option 2: NULL encryption
Option 3: TLS encryption
Option 4: IPSec encryption
Explanation: According to the security architecture for trusted non-3GPP access, since the TNAP is a trusted entity and Layer-2 security between UE and TNAP is assumed to be enabled, NULL encryption is sufficient for the user plane and signalling between the UE and TNGF.