Secure Shell (SSH) is a cornerstone of secure remote access in Linux environments. While password-based authentication is common, SSH key authentication offers superior security and convenience. By using cryptographic keys instead of passwords, you eliminate the risk of brute-force attacks and simplify logins with automation. In this guide, we’ll explore how to create SSH keys, perform an SSH key exchange, and configure the sshd_config file for key-based login. Whether you’re a system administrator or a Linux enthusiast, this deep dive will equip you with everything you need to master SSH key authentication.

What Is SSH Key Authentication?

SSH key authentication relies on a pair of cryptographic keys: a private key (kept secret on your local machine) and a public key (shared with the remote server). When you attempt to log in, the server verifies your private key against the public key, granting access without requiring a password. This method is not only more secure but also ideal for scripts and automated tasks.

In this article, we’ll break down the process into three main sections:

1. Generating SSH Keys in Linux
2. Performing an SSH Key Exchange
3. Configuring sshd_config for Key-Based Login

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