# HTTPS

> The padlock in your browser: web traffic nobody in between can read.

- Level: Basic
- Topics: Security, Networks
- URL: https://tidbit.legios.com.ar/https/
- In Spanish: [HTTPS](https://tidbit.legios.com.ar/es/https/)

**HTTPS** is plain HTTP (the language browsers and websites speak) wrapped in encryption, using a protocol called **TLS**. When you open a site with the padlock, your browser and the server first agree on a secret key that only they know, then every request and response is scrambled with it.

Anyone sitting in the middle (the café Wi-Fi, your internet provider, a hacker on the same network) sees that you are talking to a site, but not what you send: no passwords, no card numbers, no page content.

HTTPS also proves identity. The server shows a **certificate** signed by an authority your browser trusts, so you know you are talking to your bank and not to a copy of it. Since Let's Encrypt made certificates free in 2015, almost the whole web moved to HTTPS.

## An analogy

Sending a letter in a locked box where only you and the recipient have the key. The mail carrier still delivers it, but can only see the address, never the letter.

## Keep in mind

- HTTPS = HTTP + TLS encryption. The padlock means the connection is encrypted.
- It hides what you send, not which site you visit.
- Certificates prove the site is who it says it is.

## Go deeper

- [How HTTPS works (comic)](https://howhttps.works/)
- [Let's Encrypt: how it works](https://letsencrypt.org/how-it-works/)

## Related terms

- [HTTP](https://tidbit.legios.com.ar/http/): The request-and-response language browsers and websites speak.
- [Web browser](https://tidbit.legios.com.ar/web-browser/): The app that fetches web pages from the internet and draws them on your screen.
- [Encryption](https://tidbit.legios.com.ar/encryption/): Scrambling data so that only someone with the key can read it.
- [Server](https://tidbit.legios.com.ar/server/): A computer whose job is to answer requests from other computers, all day, every day.
- [Wi-Fi](https://tidbit.legios.com.ar/wi-fi/): Networking over radio waves: the internet without the cable, within a few rooms.
- [ISP](https://tidbit.legios.com.ar/isp/): The company you pay to connect your home or phone to the internet.
- [Hacker](https://tidbit.legios.com.ar/hacker/): Someone who takes systems apart to see how they work, for better or for worse.
- [TLS certificate](https://tidbit.legios.com.ar/tls-certificate/): The ID card a website shows your browser to prove it is who it claims to be.