TLS

Abbreviation · Security & Infosec · Origin: 1999

Definitions

  1. TLS, or Transport Layer Security, is the cryptographic protocol that secures communications over the internet, providing privacy, data integrity, and authentication between two communicating applications. TLS is the successor to SSL and is the protocol actually used when you see HTTPS in your browser's address bar. During a TLS handshake, the client and server agree on a cipher suite, the server presents its certificate (verified against trusted Certificate Authorities), and both parties derive session keys used for symmetric encryption of the data that follows. TLS 1.3, the latest version, simplified the handshake to a single round trip, removed insecure cipher suites, and improved performance compared to TLS 1.2. TLS protects against eavesdropping, tampering, and impersonation. It is used not only for HTTPS web traffic but also for securing email (SMTP over TLS), database connections, VPN tunnels, and API communication. Properly configuring TLS, including choosing strong cipher suites and managing certificate rotation, is a fundamental part of securing any production system.

    In plain English: The encryption technology that makes websites secure (the padlock in your browser) — protects data as it travels between your computer and a server.

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