SSLTLS

SSL/TLS is a cryptographic protocol family designed to provide secure communications over a computer network. It offers confidentiality, data integrity, and authentication through a combination of public-key cryptography, symmetric encryption, and certificates. SSL was developed by Netscape in the 1990s; TLS is its successor, standardized by the Internet Engineering Task Force. Versions have evolved from TLS 1.0 to TLS 1.2 and TLS 1.3, with SSL 3.0 and earlier now considered obsolete.

Operation and architecture: TLS typically runs on top of transport protocols such as TCP (and in the datagram world, DTLS over UDP). A handshake negotiates the protocol version and supported cipher suites, authenticates the server (and optionally the client) using X.509 certificates, and establishes a shared session key. Ephemeral key exchanges (such as ECDHE) provide forward secrecy. Once established, data is transmitted using symmetric encryption (for example AES-GCM or ChaCha20-Poly1305) with the session key, along with integrity protection.

Versions and security: TLS 1.3 introduced a streamlined handshake, removed many legacy algorithms, and improved performance and security. TLS 1.0 and 1.1 are deprecated in many contexts, and servers and clients are encouraged to use TLS 1.2 or 1.3. Although the term SSL is still used informally, modern secure communications rely on TLS rather than SSL.

Usage and deployment: TLS is widely used to secure web traffic (HTTPS), email protocols (IMAPS, SMTPS), and other Internet services. Security depends on proper certificate management, trusted authorities, and careful configuration of cipher suites and protocol versions to enable forward secrecy and avoid weak or deprecated algorithms.