Money Controls SCH2, Техническое руководство

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SCH2 Technical Manual TSP016.doc Issue 3.0 – January 2005
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Money Controls 2005. All rights reserved.
Page 19 of 61
Command = Dispense hopper coins
Transmitted data : [ 1A ] [ 77 ] [ EC ] [ F8 ] [ B9 ] [ 01 ] [ D6 ] [ FA ] [ 14 ]
Received data : [ 5 ] - example event counter
The next time we pay out a coin the cipher key will have changed, so unless the algorithm is
known, simple command ‘cloning’ will not work.
In practice, the CMF will be far more complex than this example and will require considerable
computing power and a long observation period to ‘crack’. Firing random data at the hopper will
also prove fruitless as there are astronomical odds against a successful code match.
Money Controls is realistic enough to appreciate that eventually the CMF may fall into the wrong
hands whether though huge computing resource or through leaked documentation. We have
embedded into our system an undocumented mechanism for changing the CMF in response to
future industry needs without any change to hardware.
An obvious hack would be to intercept and change the number of coins dispensed by the
‘Dispense hopper coins’ command to a greater value. This has been taken care of in the
security algorithm and will not work.
Please Note:-
A version of Serial Compact Hopper 2 is available WITHOUT Encryption.
Please refer to cctalk.org for further information.