In article <199705040245.WAA13603@Twig.Rodents.Montreal.QC.CA> you write:
> >>> [...] then the encryption/decryption key (the cd was used as a otp)
> >>> was simply an offset into the cd's data.  cute, eh?
> 
> Personally, I don't like this, unless the cd is a write-once CD and a
> given piece of the key is destroyed after being used.  Leaving the key
> accessible to anyone but the intended recipient is a Very Bad Idea.

In the Clancy book, special CD-ROM drives were used with a
higher-powered follow-behind laser that simply erased the bits used
already. When an entire CD was finished, they'd put it in a microwave
oven to be sure there was nothing left.

For typical not-quite-so-paranoid use, it'd be enough to rely on your
physical security though, otherwise you're likely hosed anyway.