Changes the backup encryption key:
$ hb rekey -c backupdir [-k key] [-p ask/env]
Typically, the -k option is not used and a new random key is generated. This is more secure than specifying a key but it also requires that you store the key in a safe place. Use the -k option to specify your own encryption key, for example, -k 'this is my new key'. The quotes are required if the key contains spaces or other special characters. To set a blank key, use -k '' (two single quotes). With a blank key, your backup is still encrypted, but anyone with access to your backup files could run HashBackup and restore your data by creating a blank key file. After changing the key, the old key file is renamed to key.conf.orig and the rekeyed database is uploaded to all remote destinations configured in dest.conf.
Use the -p option to set a passphrase. The passphrase protects your key in situations where others may have access to your backup key. Examples of this are if you rent a VPS (Virtual Private Server), have a managed server someone else administers, or write your backup directly to remote storage such as Google Drive. See the init command for more information.