Duplicity (software)
Duplicity is a software suite that provides encrypted, digitally signed, versioned, remote backup of files requiring little of the remote server. Released under the terms of the GNU General Public License, Duplicity is free software.
Duplicity devises a scheme where the first archive is a complete backup, and subsequent backups only add differences from the latest full or incremental backup. Chains consisting of a full backup and a series of incremental backups can be recovered to the point in time that any of the incremental steps were taken. If any of the incremental backups are missing, then the incremental backups following it cannot be reconstructed. It does this using GnuPG, librsync, tar, and rdiff. To transmit data to the backup repository, it can use SSH/SCP/SFTP, local file access, rsync, FTP, Amazon S3, Google Cloud Storage, Rackspace Cloud Files, and others.
Duplicity works best under Unix-like operating systems, though it can be used with Windows under Cygwin or the Windows Subsystem for Linux. Currently duplicity supports deleted files, full Unix permissions, directories, and symbolic links, fifos, and device files, but not hard links.
Déjà Dup is a graphical user interface for Duplicity.
