Question: What is the primary purpose of the f2 cryptographic function supported by the Universal Subscriber Identity Module (USIM) as defined in 3GPP security standards?
Option 1: To compute the Cipher Key (CK) for data encryption
Option 2: To compute the Signed Response (SRES) for user authentication
Option 3: To generate the Anonymity Key (AK) for optional anonymity procedures
Option 4: To facilitate re-synchronization with the network
Explanation: The f2 cryptographic function is specifically designed for user authentication, and its primary purpose is to compute the Signed Response (SRES), which is a critical component in verifying the user's identity during the authentication process. This highlights the importance of f2 in ensuring secure access to network services from the User Equipment (UE).