thoughts on one time pads

Dave Howe DaveHowe at
Sat Jan 28 11:58:41 EST 2006

John Denker wrote:
> Dave Howe wrote:
>> Hmm. can you selectively blank areas of CD-RW?
> Sure, you can.  It isn't soooo much different from rewriting any
> other type of disk.
Yeah, I know. just unsure how effective blanking is on cd-rw for (say) a pattern
that has been in residence for two years, but now must be unrecoverable.

> There are various versions of getting rid of a disk file.
>  5) Grinding the disk to dust.  AFAIK this is the only NSA-approved
>   method.  A suitable grinder costs about $1400.00.
for most, scratching off the carrier substrate is usually enough - I *might* be
persuaded some trace remains on the plastic disc afterwards, but I can't imagine
anyone recovering from a disk that had been
a) scraped clean then
b) thrown into a blast furnace containing liquid iron, or even a small home smelter.

However, I am more interested in methods to destroy just a single track at a
time, and I doubt you could deface the disk reliably *and* still retain read
abilty on the remaining tracks.

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