Lee Winter wrote: > On Sun, Sep 6, 2009 at 3:42 PM, Sven Joachim <svenj...@gmx.de > <mailto:svenj...@gmx.de>> wrote: > [snip] > > Jumping into that discussion, here is evidence that this is not > possible > with modern drives: > > > http://www.h-online.com/news/Secure-deletion-a-single-overwrite-will-do-it--/112432 > > > No, that it not evidence. It is an opinion; possibly a very informed > opinion. But security issues often require a skeptical perspective. > In this case an expert's statement that he does not know how to > retrieve info from a drive is abolutely worthless in determining > whether anyone else knows how to retrieve info from a drive. > > [snip]
> That will work up to the value of the information being secured. But > once the value of the information reaches an upper limit then it > becomes worthwhile for people to use more sophisticated techniques, > and overwriting with a constant pattern becomes worthless. > > There is a recently revised NIST standard for securing information. > It says very little -- propably because the US givernment has an > interest in lowering other entities security. The previous versions > of that standard were a lot more informative and useful. > > BTW, no sensible person ever said that 35 passes were necessary and/or > useful. A well-informed and well-intentioned expert answered a silly > question and his answer boils down to the (valid) claim that it is not > possible for any drive to require more than 35 passes. The total of > 35 was obtained by summing all of the possible overwrite techniques > for all possible drive/recording technologies. After that many > non-sensible people claimed that 35 passes was the ne-plus-ultra in > disk scribbing, which claim is both invalid and stupid. > > Lee Winter > NP Engineering > Nashua, New Hampshire Not a fan of Peter Guttman, I take it. He is pretty well known in the fields of computer security and data deletion. Here is a link to his paper. http://www.cs.auckland.ac.nz/~pgut001/pubs/secure_del.html Chris
