Tips for securing your SSH server
Protected Session

An SSH server facing the Internet will almost certainly be under attack, but a few proactive steps will help to keep the intruders away.
Secure Shell, better known as SSH, is a secure communication protocol used to execute commands on remote servers. SSH works on a client/server architecture. Data transferred through SSH is automatically encrypted using symmetric, asymmetric, and hashing algorithms. At receiving end, the data is automatically decrypted.
About 90 percent of system administrators use SSH to access their servers and configure them remotely. Users overwhelmingly prefer SSH over Telnet, an alternative communication protocol that is now considered insecure. SSH makes the data in transit more secure, but if you wish to secure an SSH server, you need to take some additional steps. Following are some measures that will help you protect your SSH server from attack.
Public Keys Instead of Passwords
The article on "System Hardening" elsewhere in this issue mentioned the benefits of using key authentication rather than passwords with SSH. Your password can be cracked by intruders, and you could end up getting hacked by a simple brute-force password attack. Here is a quick reprise on how to set up key-based authentication.
[...]
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
-
Debian 13.0 Officially Released
After two years of development, the latest iteration of Debian is now available with plenty of under-the-hood improvements.
-
Upcoming Changes for MXLinux
MXLinux 25 has plenty in store to please all types of users.
-
A New Linux AI Assistant in Town
Newelle, a Linux AI assistant, works with different LLMs and includes document parsing and profiles.
-
Linux Kernel 6.16 Released with Minor Fixes
The latest Linux kernel doesn't really include any big-ticket features, just a lot of lines of code.
-
EU Sovereign Tech Fund Gains Traction
OpenForum Europe recently released a report regarding a sovereign tech fund with backing from several significant entities.
-
FreeBSD Promises a Full Desktop Installer
FreeBSD has lacked an option to include a full desktop environment during installation.
-
Linux Hits an Important Milestone
If you pay attention to the news in the Linux-sphere, you've probably heard that the open source operating system recently crashed through a ceiling no one thought possible.
-
Plasma Bigscreen Returns
A developer discovered that the Plasma Bigscreen feature had been sitting untouched, so he decided to do something about it.
-
CachyOS Now Lets Users Choose Their Shell
Imagine getting the opportunity to select which shell you want during the installation of your favorite Linux distribution. That's now a thing.
-
Wayland 1.24 Released with Fixes and New Features
Wayland continues to move forward, while X11 slowly vanishes into the shadows, and the latest release includes plenty of improvements.