SSL

Definitions

1. SSL, or Secure Sockets Layer, is a deprecated cryptographic protocol originally developed by Netscape in the 1990s to encrypt communications between web browsers and servers. SSL introduced the concept of a secure handshake, where the client and server negotiate encryption algorithms, exchange certificates, and establish a shared secret key before transmitting any application data. Although SSL has been superseded by TLS (Transport Layer Security), the term 'SSL' is still widely used colloquially to refer to encrypted web connections and certificates. SSL/TLS certificates, issued by Certificate Authorities, verify the identity of a server and enable the HTTPS padlock icon in browsers. All modern browsers and servers use TLS 1.2 or 1.3, as SSL 2.0 and 3.0 contain known vulnerabilities like POODLE and DROWN. Understanding SSL's legacy is important because many tools, libraries, and configuration options still use the SSL naming convention even though TLS is the actual protocol in use.

   In plain English: The old name for the encryption that puts the padlock icon in your browser. Technically it is called TLS now, but everyone still says SSL.

   Example: "We need to renew the SSL cert before Friday or the site will show a scary browser warning."

Related Terms

• TLS
• Certificate
• HTTPS
• mTLS
• Certificate Transparency
• Bitlocker
• Disk Encryption
• DTLS
• Encryption at Rest
• Encryption in Transit
• End-to-End Encryption
• HTTPS Inspection
• PGP
• Temporal Key Integrity Protocol
• Transport Layer Security
• Wi-Fi Protected Access
• Certbot
• Cloud Key Management
• Deep Web
• DoT
• Heart Bleed
• HPKP
• OpenSSL Security
• Plaintext Attack
• Point-to-Point Encryption