nuke is a small disc utility for RISC OS that allows you to erase
files from the disc surface, filling their sectors with '0's or with a
user-definable string. In fact, while it is quite difficult to properly
'undelete' a file after it has been deleted using the standard RISC OS
commands or filer, it is relatively easy to search for some 'sensitive' string
in the free disc space.
New nuke 1.40 available now!
In other words, a 'plain' file delete means that the file's directory entry
has been removed and the discs sectors it used have been returned to the free
space pool. Hence, everybody with a disc editor can still find the content of
the deleted file somewhere on the disc and while some kind of data is hard to
recognise, text files (eg. emails) and even images (eg. GIFs, JPEGs) and
archives (eg. ZIP files) are rather easy to spot.
nuke allows you to erase files in a definitive way so that no disc
editor or 'undelete' utility will ever be able to restore the original file's
content. While this may not be useful for most 'home users', it may be of
particular interest to people that use 'public' computers (eg. school,
libraries) or that are particularly concerned about their 'private' data in
any kind of 'open' environment (possibly coupled with some kind of encryption
In order to cover any possible requirement from the user, nuke
- files/directories nuking
- free space nuking (in order to wipe out all the data of files previously deleted in a 'plain' way)
- single overwrite with '0's, with a user-specified number or string or with a random pattern
- multiple overwrite
- 'military-level' security, including the 35 different overwrite patterns
suggested by Peter Gutmann in his Secure Deletion of Data from Magnetic and Solid-State Memory paper
nuke works only on FileCore E-Format filesystems (eg. ADFS, EADFS,
ATAFS, BDFS, SCSI, SCSIFS, etc.), so it doesn't work on image filing systems
and (obviously!) on remote network filing systems.
nuke requires RISC OS 3.1 or later, including RISC OS 4. Even if it
hasn't been fully tested, nuke should work on discs formatted
with RISC OS 4 (ie. with long filenames and 'big' directories).
To date, nuke is the only disc-related tool I've written that fully
supports RISC OS 4. Although fsck
and RealCount are more widely used than nuke
and the former is even ShareWare, they are both much more complex than
nuke and so updating them will cost me too much time (both for
development and especially for testing and debugging). So, I have no plans,
at the moment, to make fsck and
RealCount fully RISC OS 4 compatible.
Since nuke is a command line tool,
Tony Hopstaken wrote a WIMP frontend
for it in order to make its use easier.
Nat Queen uses nuke
in two of his security-related programs, Q-Lock and Mail-Lock, in order to
properly delete the plain files after they have been encrypted.
You can find all these programs on Nat's
PGP and security utilities
nuke is FreeWare: you can use and distribute it freely,
provided that the whole archive (as downloaded from this page) is copied
You can download the latest version from this page: