Nuke is a small utility that overwrites files on disc, making them impossible to recover. This is useful when it is desirable to remove all traces of sensitive data. When a file is "deleted" by RISC OS, the reference to it is removed from the directory, but the actual file still remains on the disc surface and can easily be recovered by suitable software, until the same sectors on the disc are eventually overwritten by new files. Nuke makes such file recovery impossible, and it offers more powerful options than PGP's simple "wipe" facility, with true "military" levels of security. It can also overwrite all data from the free space on a disc, i.e. all previously "deleted" files.