shred (Unix)
This article includes a list of general references, but it lacks sufficient corresponding inline citations. (March 2015) |
Developer(s) | Colin Plumb |
---|---|
Repository | |
Cross-platform | |
Type | Command |
License |
shred is a command on Unix-like operating systems that can be used to securely delete files and devices so that it is extremely difficult to recover them, even with specialized hardware and technology; assuming it's even possible to recover the file at all. It is a part of GNU Core Utilities.[1] Being based on the Gutmann method paper,[1] it suffers from the same criticisms and possible shortcomings.
Background
For efficiency, the process of erasing a file from
Features
shred can be invoked either on ordinary files or on devices (such as hard disk partitions), which are represented as files in Unix. By default, the command overwrites the file three times with multiple patterns, but the number is user configurable. It has an option to do an additional final overwrite with zeroes, which may help to hide the fact that it was used.
By default, shred also shreds
Limitations
A limitation of shred when invoked on ordinary files is that it only overwrites the data in place without overwriting other copies of the file. Copies can manifest themselves in a variety of ways, such as through manual and automatic backups, file system snapshots, copy-on-write filesystems,
Gutmann method, which shred is based on, is known to fail on
Alternatives
The scrub
command overwrite sequence of data being compliant with a Dec. 2005 draft of National Nuclear Security Administration Policy Letter NAP-14.x. Written by Jim Garlick of
See also
References
- ^ a b c "shred invocation (GNU Coreutils 9.3)". www.gnu.org.
- Wikidata Q115346857. Retrieved 2018-01-08.
- ^ FreeBSD General Commands Manual –
- shred invocation, GNU Coreutils. Accessed February 3, 2009.
- Shred and secure-delete, Free Software Magazine. November 29, 2008. Accessed February 3, 2009.
- Secure Erase Definition Archived 2012-11-18 at the About.com. Accessed April 17, 2012.
- How To Completely Erase a Hard Drive Archived 2012-11-18 at the About.com. Accessed April 17, 2012.