What TCP port is used by HTTPS and why is TLS important?

• A. Port 80; TLS provides encryption for data at rest.
• B. Port 443; TLS provides encryption and integrity for data in transit.
• C. Port 22; TLS provides authentication only.
• D. Port 25; TLS is not used with HTTPS.

Answer: (B)

HTTPS uses TLS to secure web traffic as it travels over a TCP connection. The default port for this encrypted traffic is 443, which is why that option is the best choice. TLS provides encryption to keep the data hidden from anyone listening on the network and integrity to detect any tampering along the way, so you know the data you receive is the data the server sent. It also authenticates the server, helping you verify you’re communicating with the legitimate site (and it can also support client authentication in some setups).

Data at rest isn’t protected by TLS in transit—that’s covered by other security measures like disk encryption. The other ports listed correspond to unencrypted HTTP (port 80), SSH (port 22), or SMTP (port 25) and don’t reflect HTTPS’s standard use.