[GreenKeys] ID TTY Crypto Box..?

[Bob Camp]

Hi

Well I suspect there is somebody here who knows more about this gizmo 
than I do. That said, here's a guess:

It's an XOR (exclusive or) five or six level encoder / decoder.

You take a code tape and the tape you want to send. Both tapes go 
through readers at the same time. Each bit of the code tape controls 
weather you invert or don't invert the corresponding bit in the tape 
you want to send.

On the other end of the circuit you take an identical code tape and run 
it and the received tape through an identical box. The output of this 
box is the same as the tape you wanted to transmit. Each bit is either 
inverted (to put it back the way it was) or not inverted (leaving it in 
the correct state).

Assuming you use a truly random code tape *and* only use it once the 
code system is unbreakable. The Russians got the first part right, but 
ran out of tapes at the end of WWII so they started re-using them. The 
result was an easily broken code.

The six level encoder either is used for six level code or to encode 
the start or stop bit .  With the start or stop bit encoded you have a 
real fun time if you loose synchronization.

Of corse to be sure of what it is we would need to trace out the wiring.

	Take Care!

		Bob Camp
		KB8TQ



On Dec 6, 2004, at 5:41 PM, John Poulton wrote:

> Can you guys identify the crypto mystery box show in the pix:
>
> http://www.cs.unc.edu/~jp/pix1/crypto.back.jpg
> http://www.cs.unc.edu/~jp/pix1/crypto.front_closed.jpg
> http://www.cs.unc.edu/~jp/pix1/crypto.front_open.jpg
>
> What the heck IS this thing?  It has sockets for 3
> polar relays inside the doors on each side.  It's fairly
> light--no more than #15 or so max--so there can't be all
> that much inside.
>
> So.. if you can id this thing, would you like to own it?
> $20 + shipping, including the 5 polar relays presently
> on board.
>
> Best 73,  John Poulton K4OZY, Chapel Hill, NC
>
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