|project_name| is a secure backup program for Linux, FreeBSD and Mac OS X. |project_name| is designed for efficient data storage where only new or modified data is stored.
- Space efficient storage
- Variable block size `deduplication`_ is used to reduce the number of bytes stored by detecting redundant data. Each file is split into a number of variable length chunks and only chunks that have never been seen before are compressed and added to the repository.
- Optional data encryption
- All data can be protected using 256-bit AES_ encryption and data integrity and authenticity is verified using `HMAC-SHA256`_.
- Off-site backups
- |project_name| can store data on any remote host accessible over SSH as long as |project_name| is installed.
- Backups mountable as filesystems
- Backup archives are :ref:`mountable <attic_mount>` as `userspace filesystems`_ for easy backup verification and restores.
- Deduplication
- Deduplication is a technique for improving storage utilization by eliminating redundant data.
- Archive
- An archive is a collection of files along with metadata that include file
permissions, directory structure and various file attributes.
Since each archive in a repository must have a unique name a good naming
convention is
hostname-YYYY-MM-DD.
- Repository
- A repository is a filesystem directory storing data from zero or more archives. The data in a repository is both deduplicated and optionally encrypted making it both efficient and safe. Repositories are created using :ref:`attic_init` and the contents can be listed using :ref:`attic_list`.
- Key file
- When a repository is initialized a key file containing a password protected encryption key is created. It is vital to keep this file safe since the repository data is totally inaccessible without it.