SSL/TLS
SSL (Secure Sockets Layer) and TLS (Transport Layer Security) are cryptographic protocols that secure communication over the internet by encrypting data exchanged between clients (like web browsers) and servers. TLS is the modern, more secure successor to SSL, though the term “SSL” is still widely used informally. These protocols protect sensitive information — such as login credentials, payment details, and personal data — from eavesdropping, tampering, and forgery. Every time you see https:// and a padlock icon in a browser, SSL/TLS is at work ensuring the connection is confidential and authenticated.
How it works
- Handshake: The browser and server agree on encryption methods and exchange digital certificates to verify identities.
- Key Exchange: A shared session key is established securely using asymmetric cryptography.
- Data Encryption: All further communication is encrypted with the session key (symmetric encryption for speed).
- Integrity Check: Messages include cryptographic checksums to detect tampering.
Why it matters
SSL/TLS forms the backbone of secure online communication. Without it, sensitive data like credit card numbers or personal details could be intercepted by attackers. TLS not only encrypts data but also authenticates the server (and sometimes the client), ensuring users are communicating with the intended party. It is essential for protecting privacy, securing online banking, enabling e-commerce, and maintaining trust in digital services.
Examples
- HTTPS websites secured with TLS certificates issued by trusted Certificate Authorities.
- Encrypted email services using TLS for secure transmission between mail servers.
- VPNs and APIs that require encrypted traffic for compliance and security.