🚀 go-pugleaf

I was thinking about this are recently.  It occured to me that the
bottom bit of each sample on a CD or DAT tape is an obvious channel.

Suppose I have an ``ideal'' random bit generator, of a quality
sufficient to use as a one-time pad.  Suppose I strip off the bottom bit
of each sample in a piece of music on CD and replace it with my ideal
random bits, and press the CDs.  [[ Notice that Russia and other Warsaw
Pact countries made much foreign exchange by selling cheap CDs. ]]  The
sound will be essentially unaffected, and may even be improved because I
have just applied excellent quality dithering.  It's trivial to extract
the bottom bit out again.  In fact, I could ship messages to all my
agents on a known CD (they just go and buy it!) and they decode it with
another CD.

But how would they send messages back?  Just do the same trick on DAT or
DCC --- ship some music with the bottom bit dithered.

Excellent!

And the gear required beyond a standard CD machine and standard DAT
machine would fit on a single 1" square ASIC.

ian