SSH is a protocol for securely logging into remote computers, transferring files, and executing commands over a network. It encrypts communications, preventing eavesdropping and ensuring security.

This guide explains how to generate keys for use with SSH.

# Setting the Encryption Algorithm and Key Length

You can generate a key using the ssh-keygen command. The following example generates a key using the RSA encryption algorithm with a key length of 4096.

ssh-keygen -t rsa -b 4096

The encryption algorithm can be specified with the -t option. Available algorithms include:

• RSA
• DSA
• ECDSA
• Ed25519

The key length can be specified with the -b option.

# Setting the Save Location and File Name

Enter file in which to save the key (<home-directory>/.ssh/id_rsa): [<save-location-and-file-name>]

You will be prompted to enter a save location and file name for the key. Press Enter to accept the default location if you do not wish to specify one.

# Setting the Passphrase

Enter passphrase (empty for no passphrase): [<passphrase>]
Enter same passphrase again: [<passphrase>]

You will be prompted to set a passphrase. Setting a passphrase protects the private key. If you do not want to set a passphrase, simply press Enter.

# Key Generation

Your identification has been saved in <path-to-private-key>.
Your public key has been saved in <path-to-public-key>.
The key fingerprint is:
<display-fingerprint>
The key's randomart image is:
<display-randomart-image>

If you see this message, the key generation is complete. By default, a private key named id_rsa and a public key named id_rsa.pub will be created in the .ssh directory. By registering the public key on the remote host, you can establish secure SSH connections.