Transport Layer Security (TLS) is a protocol that secures internet communications, protecting sensitive data from interception, tampering, and unauthorized access across networks. TLS is a cryptographic protocol that establishes secure communication channels between systems over untrusted networks, encrypting data transmissions, authenticating communicating parties, and ensuring message integrity across email, web browsing, messaging applications, and cloud services.
As the successor to Secure Sockets Layer (SSL), TLS serves as the backbone of secure internet communications, protecting billions of daily transactions from cyber threats.
How TLS Works: TLS operates through a handshake process where communicating parties negotiate cryptographic parameters, exchange certificates for authentication, and establish shared encryption keys. Once the handshake is complete, all data exchanged between the parties is encrypted and integrity-protected.
TLS Handshake Process
Client Hello: The client sends supported TLS versions, cipher suites, and a random value to the server
Server Hello: The server selects the TLS version and cipher suite, sends its digital certificate, and a random value
Authentication: The client verifies the server's certificate against trusted certificate authorities
Key Exchange: Both parties derive shared session keys from the exchanged information
Encrypted Communication: All subsequent data is encrypted using the negotiated session keys
TLS Versions: TLS 1.3 is the current recommended standard, offering improved security and performance over earlier versions. TLS 1.0 and 1.1 are deprecated and considered insecure.
TLS in Email Security: TLS is used to encrypt SMTP connections between email servers (opportunistic TLS) and between email clients and servers (enforced TLS). However, TLS only encrypts email in transit—it does not protect against phishing content or malicious attachments. Pangratis protects against email-based threats that TLS alone cannot address, such as social engineering attacks and business email compromise.