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DTLS

DTLS (Datagram Transport Layer Security) extends TLS to UDP-based applications while maintaining encryption and integrity protection.

Features

  • UDP support
  • TLS-based security
  • Packet loss tolerance
  • Replay protection
  • Low-latency encryption

Common Use Cases

Secure SIP and RTP communications.

Browser real-time communications.

Lightweight secure UDP traffic.

DTLS-based VPN tunnels.

DTLS Architecture

graph LR
    A[Client] --> B[UDP Network]
    B --> C[DTLS Server]

Topics Covered

  • OpenSSL DTLS
  • DTLS handshakes
  • UDP encryption
  • Replay protection
  • Packet loss handling
  • DTLS troubleshooting

Example DTLS Server

openssl s_server -dtls -accept 4444 -cert cert.pem -key key.pem

Example DTLS Client

openssl s_client -dtls -connect 127.0.0.1:4444

Note

DTLS is specifically designed to handle unreliable UDP transport.