Some readers get confused by protocols used on the internet, like HTTP, HTTPS, and TLS. So, what is the meaning of these abbreviations?
The Hypertext Transfer Protocol is the foundation of the World Wide Web. Most communication in your web browser happens via HTTP.
- HTTP/1.1: Version 1.1 of HTTP was documented in 1997. It was the standard for HTTP communication for nearly 20 years.
- HTTP/2 (SPDY): Version 2 of HTTP was published in 2015. HTTP/2 changes the way of transmitting data between web servers and clients to minimize requests and speed up communication. Most other semantics of HTTP/1.1 stayed the same. HTTP/2 was derived from Google’s experimental SPDY protocol.
- HTTP/3 (QUIC): Version 3 of HTTP is currently available as a draft. It is derived from Google’s experimental QUIC protocol. Contrary to HTTP/2, there are more changes to speed up web communications. For instance, HTTP/3 uses UDP as the underlying transport protocol. The original QUIC protocol also integrates the key exchange and cryptographic handshake in the connection’s initial handshake, further speeding up HTTPS.
The Hypertext Transfer Protocol Secure is an extension of HTTP. Nowadays, it uses TLS (Transport Layer Security) for security. In other words: HTTPS is HTTP running on top of TLS.
- SSL: All versions of SSL are outdated. Do not use it.
- TLS 1.0 and 1.1: TLS 1.0 and 1.1 are also outdated. Do not use them.
- TLS 1.2: TLS 1.2 was introduced in 2008. While TLS 1.2 can still be considered “secure,” it comes with many legacy cipher suites that are insecure or weak. As a server admin, you need to limit the TLS cipher suites to the small number of cipher suites that support AEAD.
- TLS 1.3: TLS 1.3 is the latest TLS protocol, introduced in 2018. TLS 1.3 introduces modern cryptographic primitives and removes legacy cryptography by default. As a server admin, you don’t need to limit cipher suites.
- RFC 7540 – Hypertext Transfer Protocol Version 2 (HTTP/2)external link
- Hypertext Transfer Protocol Version 3 (HTTP/3) (draft)external link
- RFC 8446 – The Transport Layer Security (TLS) Protocol Version 1.3external link