On Tue, 2005-07-26 at 13:41 -0400, Scot L. Harris wrote: > On Tue, 2005-07-26 at 13:09, Laurence wrote: > > On Tue, 2005-07-26 at 08:09 -0600, Robin Laing wrote: > > > Mike McCarty wrote: > > > > Is there a secure file delete available for ext3 file systems? > > > > > > > > Mike > > > > > > Possibly encrypt the data in the first place? > > > > > > http://www.linuxjournal.com/article/6481 > > > > > > -- > > > Robin Laing > > > > > > > how about opening the file & writing zeros to it? > > I don't remember the specs but there are specifications published by the > U.S. Government for what constitutes secure deletion of files from > magnetic media. This requires a certain number of rewrites over the > same sectors the file was in and I think a specific set of patterns. > > Over writing a file once is usually not sufficient. There are residual > traces of what was written to the drive that with the right tools can be > recovered in some cases. > > Of course if you are disposing of a hard drive the only secure method of > disposal is to take a hammer to it. A few years ago a study was > conducted where they bought used hard drives from ebay. A variety of > recovery methods were used and the researchers were able to recover a > wide variety of personal information including SSNs, credit cards, etc. > on a significant number of the drives purchased. > > > -- > Scot L. Harris > webid@xxxxxxxxxx > > No matter what happens, there is always someone who knew it would. > The US Department of Defense clearing standard is DOD 5220.22-M Peter Gutmann wrote a paper for USENIX that addresses this. Available at: http://www.usenix.org/publications/library/proceedings/sec96/full_papers/gutmann/ Some F/OSS option to erase data at this level are Darik's Boot and Nuke http://dban.sourceforge.net/ Wipe http://wipe.sourceforge.net/ However the only tried & true methods of being sure the data can't be recovered is either longterm exposure of the media in question to temperatures in excess of 1500 degrees C (oxy-acetylene works fine) or multiple applications of high velocity lead slugs at medium range As an added benefit, both serve to relieve stress & frustration :-) -- Tony Placilla, RHCT anthony_placilla@xxxxxxxx J.O.A.T. GPG-Key-ID: 1024D/C78F8B64 http://pgp.mit.edu Key fingerprint = A8D5 7AFF CE88 4179 C792 D9A9 F197 2A15 C78F 8B64
