[svlug] Re: 2 part Linux question

Rafael Skodlar raffi at linwin.com
Fri Jul 11 22:34:25 PDT 2003

On Fri, Jul 11, 2003 at 12:31:20PM -0700, Daniel Howard wrote:
> Yet another article on disk drive sanitization:
> "Remembrance of Data Passed: A Study of Disk
> Sanitization Practices" by Simson L. Garfinkel and
> Abhi Shelat
> Published in IEEE Security & Privacy, vol. 1, no. 1,
> 2003
> http://computer.org/security/v1n1/garfinkel.htm

While that is an interesting excercize I wonder why worry about
(supposedly) erased data on disk drives? With $1 per GB the question
comes up, what's the value of your accessible or erased data? If the
value of erased data is bigger than the cost of average size disk drive
then physicaly destroy the disk.

For average mortals worrying about recovering bank accounts, email, or
occassional juicy picture from a used drive, a simple erase and possibly
overwrite with random noise should be more than enough. Others better
opt for the physical destruction.

# To destroy or not to destroy


let level=${paranoia}*${data_value}
echo -e "Data value: \$$data_value\nDrive cost: \$$drivecost\n  Paranoia: $paranoia"
if [  "$level" -gt "$drivecost" ]; then
  echo -e "Data is too valuable for your paranoia level $paranoia\n\t>>>>> destroy the disk <<<<<\n"
  echo -e "Run\ndd if=/dev/random of=/dev/hdb bs=1024\n"


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