what is tls

Transport Layer Security (TLS) is a cryptographic protocol designed to provide secure communication over a computer network. It aims to provide security, including privacy (confidentiality), integrity, and authenticity through the use of cryptography, such as the use of certificates, between two or more communicating computer applications. TLS is mostly familiar to users through its use in secure web browsing, and in particular, the padlock icon that appears in web browsers when a secure session is established. TLS is the successor of the Secure Sockets Layer (SSL) protocol, which was originally developed by Netscape Communications Corporation in 1994 to secure web sessions. TLS is normally implemented on top of TCP to encrypt Application Layer protocols such as HTTP, FTP, SMTP, and IMAP, although it can also be implemented on UDP, DCCP, and SCTP as well (e.g., for VPN and SIP-based application) .