Question: In GPRS networks, what is the primary difference in ciphering algorithms between A/Gb mode and Iu mode?
Option 1: The use of symmetric vs asymmetric encryption
Option 2: The input key for A/Gb mode is Kc, while for Iu mode it's a derived key from CK
Option 3: A/Gb mode uses GEA with a static key, whereas Iu mode uses UEA with dynamic keys
Option 4: A/Gb mode utilizes the GPRS Encryption Algorithm (GEA) with Kc, whereas Iu mode employs the UMTS Encryption Algorithm (UEA) with CK
Explanation: The primary distinction lies in the type of encryption algorithm used (GEA for A/Gb mode vs UEA for Iu mode) and the specific key input for each (Kc for GEA in A/Gb, CK for UEA in Iu), demonstrating tailored security measures for different network modes, impacting data protection during transmission.