In SSL/TLS, what is the main advantage of using symmetric encryption for the data payload?

• A. It is easier to implement
• B. It provides better security
• C. It allows for faster data encryption and decryption compared to asymmetric methods
• D. It eliminates the need for certificates

Answer: (C)

The key idea is that TLS uses asymmetric cryptography only for establishing a secure session, then switches to symmetric encryption for the actual data transfer because it is much faster. During the handshake, public-key methods secure authentication and the exchange of a session key. Once both sides have this shared key, they encrypt and decrypt the bulk data with a symmetric cipher (like AES or ChaCha20-Poly1305), which is designed for speed. Symmetric encryption performs the same operation on both ends with far less computational overhead than public-key cryptography, allowing high throughput and lower latency for large amounts of data. That speed advantage is why the data payload is encrypted symmetrically in TLS.