Secure communication over the unreliable UDP transport with DTLS
Secret Delivery

© Lead Image © Daniel Villeneuve, 123RF.com
TLS encryption is wonderful if it is running over a reliable transport protocol like TCP; but if your needs call for the less reliable UDP transport, you'd better start learning about DTLS.
TCP/IP is at the heart of the Internet, and the Transport layer is at the heart of TCP/IP. The Transport layer is responsible for end-to-end connections between the sender and receiver over a TCP/IP network. The two most common Transport layer protocols are Transmission Control Protocol (TCP) and User Datagram Protocol (UDP). Nearly all Internet traffic uses either TCP or UDP.
TCP is connection-oriented, which means that a connection between the client and server is established before data can be sent. The TCP protocol provides reliable ordering and error-checked delivery. UDP is a connectionless protocol, which means it provides only minimal information and has no handshaking procedure. UDP does not offer a guarantee of ordering or delivery. Of course, the brevity of UDP makes it much faster than the steady and careful TCP, so applications that don't require a high level of reliability tend to use UDP.
TCP and UDP were created in more innocent days of an Internet, when networks did not face the security challenges we deal with today. The Transport Layer Security (TLS) protocol (and its predecessor SSL) were developed to provide encryption for communication security at the Transport layer. TLS offers privacy and data integrity between two communicating network nodes; however, it requires a reliable transport protocol, which means it won't work with the simple and unreliable UDP. TLS assumes that the packets arrive in the correct order, which TCP ensures but UDP does not.
[...]
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.

News
-
Gnome’s Dash to Panel Extension Gets a Massive Update
If you're a fan of the Gnome Dash to Panel extension, you'll be thrilled to hear that a new version has been released with a dock mode.
-
Blender App Makes it to the Big Screen
The animated film "Flow" won the Oscar for Best Animated Feature at the 97th Academy Awards held on March 2, 2025 and Blender was a part of it.
-
Linux Mint Retools the Cinnamon App Launcher
The developers of Linux Mint are working on an improved Cinnamon App Launcher with a better, more accessible UI.
-
New Linux Tool for Security Issues
Seal Security is launching a new solution to automate fixing Linux vulnerabilities.
-
Ubuntu 25.04 Coming Soon
Ubuntu 25.04 (Plucky Puffin) has been given an April release date with many notable updates.
-
Gnome Developers Consider Dropping RPM Support
In a move that might shock a lot of users, the Gnome development team has proposed the idea of going straight up Flatpak.
-
openSUSE Tumbleweed Ditches AppArmor for SELinux
If you're an openSUSE Tumbleweed user, you can expect a major change to the distribution.
-
Plasma 6.3 Now Available
Plasma desktop v6.3 has a couple of pretty nifty tricks up its sleeve.
-
LibreOffice 25.2 Has Arrived
If you've been hoping for a release that offers more UI customizations, you're in for a treat.
-
TuxCare Has a Big AlmaLinux 9 Announcement in Store
TuxCare announced it has successfully completed a Security Technical Implementation Guide for AlmaLinux OS 9.