Final answer:
The protocol used for secure communications over the Internet is HTTPS, which encrypts data to maintain privacy and integrity, ideal for sensitive transactions like online banking and purchasing.
Step-by-step explanation:
The most secure communications over the Internet typically use a protocol called HTTPS (Hypertext Transfer Protocol Secure).
This protocol is an extension of HTTP and incorporates SSL/TLS encryption to ensure that data transferred between the web server and browser remains private and integral.
HTTPS is commonly used for online banking, e-commerce, and any other scenarios where secure data transfer is essential.