From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,aa529428387c8116 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2002-09-17 07:49:45 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!newsfeed.icl.net!newsfeed.fjserv.net!news.tele.dk!small.news.tele.dk!129.240.148.23!uio.no!newsfeed1.uni2.dk!news.net.uni-c.dk!not-for-mail From: Jacob Sparre Andersen Newsgroups: comp.lang.ada Subject: Re: Crypting files with Ada Date: Tue, 17 Sep 2002 16:49:42 +0200 Organization: UNI-C Message-ID: <3D874106.8020809@nbi.dk> References: NNTP-Posting-Host: kaoslx07.nbi.dk Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Trace: news.net.uni-c.dk 1032274184 23198 130.225.212.98 (17 Sep 2002 14:49:44 GMT) X-Complaints-To: usenet@news.net.uni-c.dk NNTP-Posting-Date: Tue, 17 Sep 2002 14:49:44 +0000 (UTC) User-Agent: Any Browser, HTML 4.01, XHTML 1.0 X-Accept-Language: Faeroese [fo],Danish [da],Norweg.96 20000731 (Red Hat Linux 7.3 2.96-110) Xref: archiver1.google.com comp.lang.ada:29079 Date: 2002-09-17T16:49:42+02:00 List-Id: Preben Randhol wrote: > I don't know. That is sth I have to find out. The problem is that if you > simply delete a file in say Windows or Linux you don't rease it you only > delete the link. So unless the OS has overwritten the place the file > occupied with new files one can recover it. Yes. > I guess one could change every byte in the file with 0 and then write > the file again before deleting it. This would not necessarily be enough. According to a paper by Peter Gutmann, you ought to overwrite the file 35 times with different bit patterns. You can find an implementation of this here: http://www.linux-kurser.dk/secure_harddisk_eraser.html (it's written in C) Jacob -- "This page inadvertently left blank."