The Fundamentals of SSH

In a world where cybersecurity is no longer a luxury but a necessity, SSH (Secure Shell) has become a cornerstone for secure communications and remote computing. SSH emerged in the mid-90s as a successor to Telnet, an older protocol that allowed for remote access to other computers. While Telnet was groundbreaking for its time, it lacked essential security features, making it easy prey for hackers and data thieves. Today, SSH has effectively replaced Telnet and is widely used in various computing platforms, from Macs to Linux systems and even on Android devices.
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The Problem with Telnet

The genesis of SSH traces back to the limitations of its predecessor, Telnet. When Telnet was developed, it provided a way for computers to communicate remotely. However, Telnet had a significant flaw: it sent data over the internet without any encryption, making it susceptible to interception and unauthorized access. Imagine sending a note to your neighbor in an open envelope; anyone who intercepts it can read its contents without a hitch.

How SSH Ushered in a New Era of Security

SSH was developed to address the vulnerability of Telnet, and it introduced an encrypted channel for data transmission. Think of this like using a double-locked briefcase for your note instead of an open envelope. When you send a message to your neighbor, you lock the briefcase with your lock. Once your neighbor receives it, he adds his lock and sends it back to you. You then remove your lock and return the briefcase, allowing your neighbor to unlock his lock and read the message. This way, the data remains secure throughout its transit, making unauthorized access nearly impossible.

Setting Up an SSH Server

Setting up an SSH server is remarkably versatile, and you can do it on nearly any operating system. Here are quick steps for different platforms:


  • Go to “Sharing Preferences Panel” and enable “Remote Login.”


  • Install the OpenSSH server and check its status to ensure it’s running.

Raspberry Pi

  • Navigate to “RasPi Config” options and enable SSH in the “Interfaces” section.

Windows 10

  • Head over to “Apps and Features,” then “Manage Optional Features” and install the OpenSSH server. Ensure it is set to auto-start during boot.


  • You can install the Simple SSHD app for Android devices.

Connecting to an SSH Server

Once the server is set up, you’ll need SSH software on the device you’ll be using to connect. This software comes pre-installed on Mac, Linux, and Raspberry Pi. On Windows, you can check “Apps and Features” to see if it’s enabled and install if necessary. Mobile users can install an app like Terminus for SSH functionalities.

SSH Commands

After successfully logging into your SSH server, you can execute various commands depending on your server’s operating system. Here are some commonly used commands for Linux and Mac:

  • ls: List directory
  • cd: Change directory
  • mkdir: Make a new directory
  • rm: Remove a file
  • cp: Copy a file
  • nano: Opens the Nano text editor

Conclusion and Future Directions

SSH has come a long way since its inception, with an array of features and functionalities still to be explored. One intriguing aspect that we’ll discuss in a future blog post is SSH tunneling, which allows you to route your internet traffic securely through an SSH server.

Whether you’re a systems administrator or just an individual looking for secure ways to access remote systems, SSH is a critical tool in your cybersecurity arsenal. And remember, the digital world is continually evolving; therefore, so should our knowledge and strategies for maintaining a secure digital environment.

If you found this guide useful, please feel free to share it and leave your comments below. Keep an eye out for our next article, where we’ll dive deeper into the fascinating world of SSH tunneling.