SSL/TLS
The encryption protocol that secures data in transit on the web — the S in HTTPS — protecting it from eavesdropping and tampering.
Full Definition
SSL (Secure Sockets Layer) and its successor TLS (Transport Layer Security) are cryptographic protocols that authenticate parties and encrypt data in transit. Despite SSL being deprecated, the term is still commonly used. TLS 1.3 is the current version, offering faster handshakes and stronger cipher suites than TLS 1.2. The TLS handshake is a major fingerprinting surface: the ClientHello message exposes cipher suite preferences, extension order, and supported elliptic curves — collectively forming the JA3 fingerprint. Proxy servers that terminate TLS (HTTPS proxies) must present a valid certificate or the client will reject the connection.
