What is HSTS?

HTTP Strict Transport Security (HSTS) is a security feature for websites. It tells web browsers that they should only connect to the website using HTTPS, not HTTP. This makes the connection more secure by encrypting the data sent between the browser and the website. It helps protect the website and its users from attacks where data could be intercepted or tampered with.

Assuming that a user accesses a website over HTTP, (e.g., http://example.com). All the data is transmitted to the client in plaintext format, leading to man-in-the-middle attacks. HSTS helps prevent data exploitation by forcing web browsers to connect to the website over HTTPS only. All the URLs with HTTP will be blocked there.

How HSTS Works?

1. Initial Connection: When a user first visits a website, the browser connects using HTTPS.
2. HSTS Header: The website sends an HSTS header to the browser. This header tells the browser to always use HTTPS for future connections to the website.
3. Enforced Security: After receiving the HSTS header, the browser will only connect to the website using HTTPS, even if the user tries to use HTTP.