Question: In a TLS-based mutual authentication scenario between two telecom network entities, what is the primary purpose of exchanging CA certificates in a secure, out-of-band manner?
Option 1: To directly authenticate the entities without needing individual certificates.
Option 2: To establish an encrypted tunnel for subsequent data transfer between the entities.
Option 3: To enable validation of entity-specific certificates during the TLS handshake by having the corresponding CA certificates marked as trusted in the certificate store.
Option 4: To bypass the need for TLS mutual authentication altogether.
Explanation: Exchanging CA certificates allows each entity to validate the other's certificate during the TLS handshake by verifying them against trusted CA certificates stored locally, establishing trust in identities for secure mutual authentication.