The cryptographic protocol that encrypts and authenticates data sent over networks, securing HTTPS, email, and many other services.
Transport Layer Security (TLS) is the successor to the older Secure Sockets Layer (SSL) protocol, and people still often say SSL certificate when they mean a TLS certificate. When your browser connects to a website over HTTPS, a TLS handshake takes place: the server presents a certificate proving its identity, both sides agree on encryption keys, and from then on traffic is encrypted and protected from tampering.
TLS 1.3, published in 2018, simplified the handshake, made connections faster, and removed weaker older algorithms. Older SSL versions and early TLS versions are considered insecure and are disabled by modern browsers. Beyond websites, TLS protects email transfers, VPNs, APIs, and connections between services inside data centers.
The process of verifying that a user, device, or system is who or what it claims to be.
EncryptionThe process of converting readable data into scrambled ciphertext that only someone with the correct key can decode.
HTTPSHypertext Transfer Protocol Secure: the encrypted version of HTTP, the protocol browsers use to load web pages.
Man-in-the-Middle AttackAn attack in which someone secretly intercepts communication between two parties, letting them read or alter the data being exchanged.
Post-Quantum CryptographyEncryption and digital signature methods designed to resist attacks from future quantum computers while running on today's ordinary hardware.
A plain-English guide to encryption at rest and in transit, with real examples from email, phones and websites, plus the settings every small business should check.