Key exchange and authentication are fundamental aspects of secure communication, but they serve distinct purposes. The key exchange involves securely sharing encryption keys between parties to establish a secure channel, ensuring that data remains confidential and tamper-proof during transmission.
On the other hand, authentication verifies the identities of the communicating parties, ensuring that they are who they claim to be. While key exchange focuses on securing the communication itself, authentication establishes trust and prevents unauthorized access, combining to create a robust foundation for secure interactions.