Not too familiar with POS device setup so I am redirecting your  
question to the jpos mailing list. People on the list have great  
knowledge and you should get an appropriate response. Please subscribe  
to the mailing list and post questions there.

You should have a device manual that should guide you through the setup.

-chhil

On Oct 25, 2009, at 9:08 AM, Tod Myer <knocturnal4l...@gmail.com> wrote:

I would think keys would be kept in memory, not persisted anywhere and
out of 'reach' of an api the terminal would provide.

If the keys were available, then the benefit of the cryptography would
be eliminated.

What are you trying demonstrate?

--
Mark

Here is additional info that was emailed to me by Tod.

'the device manual wil never post this kind of info to find the ZMK  
for protection but im doing something in fornt of audience in few  
weeks and i want to show how insecure terminal are really with getting  
this kind of info some criminals can steal information'
-chhil

On Oct 25, 2009, at 4:28 PM, Mark Salter <marksal...@talktalk.net>  
wrote:

Having to ask how to demonstrate such weaknesses, does - I think -
highlight where some weakness lies.

There are papers indexed by google covering the problems with POS
devices, one such paper:-

   http://www.hackerfactor.com/papers/cc-pos-20.pdf

...made an interesting skim, including 'magic' key combinations for some
terminals to reset passwords.  Primarily to gain access to the stored
transactions - only brief mentions of POS storage medium and protection.

--
Mark