# TLS | | **Transport Layer Security** (TLS) is a cryptographic protocol designed to provide communications security over a computer network. The protocol is widely used in applications such as email, instant messaging, and voice over IP, but its use in securing HTTPS remains the most publicly visible. | |-|-| | | wikipedia:: [Transport Layer Security](https://en.wikipedia.org/wiki/Transport_Layer_Security) | (& SSL) [[Cryptography]], [[Security]], [[HTTP]], [[Public-key Cryptography]] - New versions of SSL are renamed TLS - when the time came to update from SSLv3.0, instead of calling the new version SSLv4.0, it was renamed TLSv1.0.  - Some people still use term "SSL" when referring to TLS - TLS 1 & 1.1 deprecated by 2020. - TLS 1.2 minimum required for HTTP2 - TLS 1.2 on about 95% of browsers as of 2018 - TLS 1.3 finalized 2018 - TLS resides on the Application Layer of the OSI model.  - private/public key based encryption - [[HTTP]]S - Browser Lock Icon [Types of SSL certificates | SSL certificate types explained | Cloudflare](https://www.cloudflare.com/learning/ssl/types-of-ssl-certificates/) [What is an SSL certificate? | How to get a free SSL certificate | Cloudflare](https://www.cloudflare.com/learning/ssl/what-is-an-ssl-certificate/)