SSH Key Gen Using ed25519

ssh-keygen -o -a 100 -t ed25519 -f ~/.ssh/id_ed25519 -C "john@example.com"

• -o: Save the private-key using the new OpenSSH format rather than the PEM format. Actually, this option is implied when you specify the key type as ed25519

• -a: It’s the numbers of KDF (Key Derivation Function) rounds. Higher numbers result in slower passphrase verification, increasing the resistance to brute-force password cracking should the private-key be stolen

• -t: Specifies the type of key to create, in our case the Ed25519

• -f: Specify the filename of the generated key file. If you want it to be discovered automatically by the SSH agent, it must be stored in the default .ssh directory within your home directory

• -C: An option to specify a comment. It’s purely informational and can be anything. But it’s usually filled with <login>@<hostname> who generated the key

Before adding your new private key to the SSH agent, make sure that the SSH agent is running by executing the following command:

eval "$(ssh-agent -s)"

Then run the following command to add your newly generated Ed25519 key to SSH agent:

ssh-add ~/.ssh/name_of_key