On 29 Oct 2002 at 12:15, John Orr wrote: Date sent: Tue, 29 Oct 2002 12:15:22 -0600 From: "John Orr" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]>, <security-basics@security- focus.com> Subject: Re: Interesting One
> Personally, I think he is full of... hot air. > > Bits are either "on" or "off", "1" or "0". If you change that pattern (i.e. write >over the same data area with a different sequence of bits), then the previous state >of that field would not be determinable. Granted, there may be some residual >magnetic field left on a particular area that is now "0" that had been "1", but the converse would not be true. There would be no residual field to read on an area that is now "1" that had been "0". > > Sounds like sales fluff to me. *small snip* Here are some links to more information concerning the recovery of data from HDDs etc. Some of the information is a little old, but should still provide for interesting reading: 'Secure Deletion of Data from Magnetic and Solid-State Memory' http://www.cs.auckland.ac.nz/~pgut001/pubs/secure_del.html (more of Peter's writing here) http://www.cs.auckland.ac.nz/~pgut001/ 'Thoughts on secure deletion in 2001 (pt2) http://www.doxpara.com/read.php/security/secure_deletion2.html 'Secure deletion of data media' http://secinf.net/info/misc/gshb/s/s2167.htm 'Ghosts' http://security.tao.ca/ghosts.shtml Cheers, -- 'When you meet someone better than yourself, turn your thoughts to becoming his equal. When you meet someone not as good as you are, look within and examine your own self....' Confucius ** Brad Griffin Gryphonn Design Computer Security Solutions Custom designed systems Ph: 0409057865/(07)4922 2589 Rockhampton QLD 4700 ABN: 12 095 821 961 [EMAIL PROTECTED] ***************************
