Which protocol is used to encrypt web communications over HTTP?

The protocol used to encrypt web communications over HTTP is Hypertext Transfer Protocol Secure (HTTPS). HTTPS is essentially HTTP enhanced with security measures, utilizing encryption protocols such as Transport Layer Security (TLS) or its predecessor, Secure Sockets Layer (SSL). This encryption ensures that data transmitted between the user's browser and the web server is secure from eavesdroppers and tampering, providing confidentiality and integrity of the information being exchanged.

In contrast, the other protocols mentioned do not serve this purpose. File Transfer Protocol (FTP) is primarily used for transferring files over a network and does not provide encryption by default. Simple Mail Transfer Protocol (SMTP) is used for sending emails, not for web communications. Lastly, Internet Control Message Protocol (ICMP) is used for network devices to send error messages and operational information, which is unrelated to web communication encryption.