How does https work step by step

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Last updated: April 8, 2026

Quick Answer: HTTPS (Hypertext Transfer Protocol Secure) works by encrypting HTTP data using TLS (Transport Layer Security) or its predecessor SSL (Secure Sockets Layer), with TLS 1.3 being the latest version as of 2023. When a user visits an HTTPS website, the browser verifies the site's SSL/TLS certificate issued by a Certificate Authority (CA), establishing an encrypted connection that protects data from interception. This encryption prevents man-in-the-middle attacks, ensuring secure transmission of sensitive information like passwords and credit card details.

Key Facts

HTTPS uses TLS/SSL encryption, with TLS 1.3 standardized in 2018
As of 2023, over 90% of web traffic uses HTTPS
SSL was first developed by Netscape in 1994
HTTPS operates on port 443 by default
Certificate Authorities (CAs) issue SSL/TLS certificates that browsers trust

Overview

HTTPS (Hypertext Transfer Protocol Secure) is the secure version of HTTP, the fundamental protocol for data communication on the World Wide Web. Developed to address security vulnerabilities in plain HTTP, HTTPS encrypts data between a user's browser and a web server, preventing eavesdropping and tampering. The technology originated with SSL (Secure Sockets Layer), first created by Netscape in 1994 for their Navigator browser. SSL evolved into TLS (Transport Layer Security), with TLS 1.0 standardized in 1999 and the latest version, TLS 1.3, finalized in 2018. Historically, HTTPS adoption was slow due to performance overhead and certificate costs, but since Google began prioritizing HTTPS sites in search rankings in 2014, adoption has accelerated dramatically. Today, HTTPS has become the standard for web security, with major browsers like Chrome and Firefox marking HTTP sites as "not secure" since 2017.

How It Works

HTTPS operates through a multi-step handshake process that establishes a secure connection. First, when a user visits an HTTPS website (typically via port 443), the browser requests the server's SSL/TLS certificate. This certificate, issued by a trusted Certificate Authority (CA), contains the server's public key and identity information. The browser verifies the certificate's validity and authenticity. Next, using asymmetric encryption, the browser and server exchange keys to establish a shared secret. This process involves the browser generating a pre-master secret, encrypting it with the server's public key, and sending it to the server. Both parties then use this secret to generate symmetric session keys. Finally, all subsequent data transmission uses symmetric encryption (typically AES) with these session keys, providing efficient encryption for the duration of the session. The entire handshake typically completes in under 100 milliseconds with modern TLS 1.3.

Why It Matters

HTTPS is crucial for protecting sensitive online activities in an era of increasing cyber threats. It prevents man-in-the-middle attacks where attackers intercept unencrypted data, protecting passwords, financial information, and personal communications. For e-commerce, HTTPS is essential for secure payment processing and building customer trust. Beyond privacy, HTTPS provides authentication through SSL/TLS certificates, verifying that users are connecting to legitimate websites rather than impostor sites. The protocol also ensures data integrity, preventing unauthorized modification of content during transmission. Since 2018, all major browsers require HTTPS for features like geolocation and camera access, making it fundamental to modern web functionality. The widespread adoption of HTTPS has transformed web security, with over 90% of page loads now protected by default.