Question: In a Service Based Architecture (SBA) using CMPv2 for certificate management, how is message integrity protection achieved for PKI messages?
Option 1: Using symmetric algorithms with shared secret information established via in-band means.
Option 2: Using asymmetric algorithms or shared secret information established via out-of-band means as defined in RFC 4210.
Option 3: Solely relying on the operator root CA certificate for encryption.
Option 4: Utilizing a combination of CMPv1 and CMPv2 protocols for dual-layer protection.
Explanation: This is correct because, according to the specified requirements for CMPv2 usage in Service Based Architecture, message integrity protection for PKI messages must use either asymmetric algorithms or, alternatively, shared secret information that has been established through out-of-band means as defined in RFC 4210. This approach ensures secure communication without relying on potentially vulnerable symmetric algorithms with in-band key exchange or solely on CA certificates for encryption.