One Time Pads $5000|Cheap

[Bill Bogstad]

Bill Stewart <9312121323.AA10300 at anchor.ho.att.com> you wrote:
>One disadvantage of CDROMs is that you lose a major advantage that real
>paper one-time pads had - once you had used a page, you could burn it.
>With a CD-ROM, presumably the whole pad *will* last you a while, and you
>probably don't want to melt the outer tracks of the disk as you use them up...
>So you either send ~600MB of secret stuff or waste the disk, depending on how 
>secure your communications needs are and how soon you expect to be busted.

	I'm not sure about the format of writable CD-ROMs; but with other
write-only media the default state of a bit is X and you write by changing
some of the bits to Y.  This being the case, you could conceivably zap part
of the disk by writting them as all Ys.  This would require everyone to have
a CD-ROM writer not just a reader.  Another problem is even if the media
itself has this capability the standard writer devices are going to want to
write block checksums etc.; which is probably going to fail.

				Bill Bogstad
				bogstad at cs.jhu.edu