Why HTTP Is Insecure and How HTTPS Secures Your Web Traffic

21CTO Community Introduction: When Google launches new technology standards, the internet changes. When it announced that sites using SSL/HTTPS would be preferred in search results, the web landscape shifted. In web development, several communication protocols exist; the most common for end users are HTTP and HTTPS. This article explains them.

What is a "protocol"

Before discussing HTTP and HTTPS, let's talk about the term "protocol". A protocol is a set of rules describing a specific purpose; in this context, the rules govern communication, similar to how people use language to understand each other.

For example, a Chinese news broadcast is understood by Chinese speakers, but not by English speakers. A protocol establishes mutually agreed communication rules so both parties can understand each other.

What is HTTP

HTTP (HyperText Transfer Protocol) defines the rules for sending and receiving text messages. Computers operate in binary, using 0 and 1 to represent data.

In HTTP, the transmitted data is plain text, which browsers parse as hypertext. HTTP can transfer images, text, audio, video, etc.

For instance, when using public Wi‑Fi at an airport, data sent via HTTP is in plain text and can be intercepted, exposing passwords if you log into a bank site.

Thus, HTTP is considered insecure.

What is HTTPS

During WWII, radio communications could be intercepted; the U.S. military used the complex Navajo language for secure transmission, similar to how HTTPS encrypts data.

HTTPS requires more complex setup, third‑party certificates, and often costs, which delayed its adoption. Today it is mandatory for most websites, and major platforms like Google, Apple, and Facebook fully support it, even HTTP/2.0.

Apple requires all apps submitted to the App Store to support HTTPS. Chrome flags non‑HTTPS sites as insecure, and even sites with weak SHA‑1 certificates receive warnings.

HTTPS uses encryption algorithms (e.g., 128‑bit, 64‑bit). While a man‑in‑the‑middle can see encrypted traffic, they cannot decipher it without the decryption key, which only the browser possesses.

What Happens When You Request an HTTP URL?

The request reaches the server, which sends text back to the browser, either in plain or encrypted form, for rendering or other purposes.

Encryption strength can be measured by bit length; higher bits mean harder decryption, though not impossible.

HTTPS provides a sense of security for personal searches, shopping, and reading, protecting privacy.

For personal, banking, or financial information, HTTPS is essential.

Advantages and Disadvantages of HTTPS

HTTPS adds overhead: decryption requires more server resources (CPU, memory) and incurs additional cost.

Without optimization, HTTPS can be roughly twice as slow as HTTP. A comparison site is http://www.httpvshttps.com/.

Common misconceptions:

My site has no transactions, so HTTPS isn’t needed.

SSL certificates are expensive.

Migrating from HTTP to HTTPS severely impacts performance.

Even sites without transactions should use HTTPS to prevent injection attacks. HTTPS can be optimized for good performance, and the trust gained outweighs the certificate cost.