TLS and SSL

Introduction

TLS, or Transport Layer Security, is the protocol used to protect communication over the internet. It is the security layer behind HTTPS and helps keep data private, unchanged, and connected to the correct server.

SSL came before TLS, but modern secure systems use TLS instead of SSL. People still casually say “SSL certificate,” but in real modern communication, the protocol being used is usually TLS.

What TLS Provides

TLS creates a secure channel between two communicating systems, such as a browser and a web server. Once the secure connection is established, application data can travel safely through it.

TLS mainly provides:

• Confidentiality: Data is encrypted so outsiders cannot read it.

• Integrity: Data changes can be detected during communication.

• Authentication: The client can verify that it is talking to the correct server.

• Session security: Temporary keys are created for protecting actual data transfer.

For example, when a user opens an HTTPS website, TLS helps protect passwords, cookies, tokens, payment details, and API responses from being exposed on the network.

SSL vs TLS

SSL and TLS are related, but they should not be treated as the same thing in secure system design. SSL is older and has been replaced by TLS.

The correct modern term is TLS. SSL is mostly used today as a legacy name in phrases like “SSL certificate” or “SSL/TLS.”