Question: What is a mandatory requirement for Cipher Suites used in the context of key establishment between a Universal Integrated Circuit Card (UICC) and a terminal, as per Network Domain Security (NDS) guidelines?
Option 1: Cipher Suites with NULL encryption are mandatory for all transactions.
Option 2: The use of Cipher Suites with NULL encryption is permitted but not recommended.
Option 3: Cipher Suites with NULL encryption shall be allowed only for specific, low-risk transactions.
Option 4: Cipher Suites with NULL encryption shall not be allowed for use.
Explanation: In the context of securing communications between a UICC and a terminal, allowing unencrypted data exchange poses significant security risks. Therefore, to maintain the integrity and confidentiality of the information, the use of Cipher Suites with NULL encryption (essentially, no encryption) is strictly prohibited, ensuring all data exchanges are encrypted to some level. This aligns with best practices in Network Domain Security (NDS), emphasizing the importance of encryption in protecting sensitive information.