Question: In accordance with 3GPP security standards for IP-based services, what is a specific requirement for the Common Name (CN) field in X.509 digital certificates used for TLS entity authentication?
Option 1: The CN shall contain the IP address of the server.
Option 2: The CN can include multiple Fully Qualified Domain Names (FQDNs).
Option 3: The CN shall be the Fully Qualified Domain Name (FQDN) of the server, with only a single FQDN allowed.
Option 4: The CN is not mandatory for TLS entity certificates.
Explanation: This requirement ensures uniqueness and clarity in identifying the server during the authentication process in TLS connections. By mandating the use of a single Fully Qualified Domain Name (FQDN) in the Common Name (CN) field, the standard enhances security by reducing ambiguity and potential misidentification of servers. This aligns with best practices for secure communication protocols in telecommunication networks.