Question: What type of protection is required for the temporary user identity (P-)TMSI during allocation time and other permitted signalling procedures to ensure identity confidentiality?
Option 1: Integrity protection
Option 2: Authentication
Option 3: Confidentiality protection
Option 4: Encryption only
Explanation: To maintain identity confidentiality, the temporary user identity (P-)TMSI must be protected from unauthorized access. Confidentiality protection ensures that sensitive information remains private and is not disclosed to unauthorized parties. This requirement is crucial for safeguarding user identities during transmission between the Mobile Equipment (ME) and the Radio Network Controller (RNC).