Sergio's Nexus
 Download  RISC OS 4
 PGP and security for RISC OS
 Secure Deletion of Data
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 RealCount  HSC
nuke: the file nuker!

New nuke 1.40 available now!

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.

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 tool).

In order to cover any possible requirement from the user, nuke features:


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.

Programs using 'nuke'

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 page.

Conditions of use

nuke is FreeWare: you can use and distribute it freely, provided that the whole archive (as downloaded from this page) is copied unaltered.


You can download the latest version from this page:
© Sergio Monesi
Updated: 10 Sep 1999