# tarsnap-keygen > Generate a key file for use with Tarsnap, an online backup service. > More information: . - Register a machine with the Tarsnap server: `sudo tarsnap-keygen --keyfile {{path/to/file.key}} --user {{user_email}} --machine {{machine_name}}` - Encrypt the key file (a passphrase will be requested twice): `sudo tarsnap-keygen --keyfile {{path/to/file.key}} --user {{user_email}} --machine {{machine_name}} --passphrased`