Re[2]: FYI: Trusted Reviews | Visa Revamps Humble Credit Card.

[Brian L Johnson]

Chris Salter <ukcrypto@originalthinktank.org.uk> wrote:

> Hello Brian and UKCrypto,
> Wednesday, November 12, 2008, 3:58:54 PM, you wrote:
>
>> I hope that the keys don't 'shine-up' with use. If they do, after a user
>> has pressed the same 4 keys over and over again, it would be possible to
>> identify the PIN.

>

> If, as described, you start the "authentication process by pressing
> the appropriate option button on the card's keypad", you may be able
> to press all the other keys prior to that i.e. even out the wear. The
> keys on the Barclay's PINsentry device (for Barclays Debit accounts)
> appears to have fairly hard wearing 'rubber-like' keys but I will now
> start the day by pressing them all at least once*!


The Barclays PINsentry has raised shiny numbers on the keys. My Nationwide  
equivalent has different shape, size, layout, power use, facilities,  
colour, etc, but nevertheless the keys appear (under a 10x loupe) to be  
made of the same sort of rubber/plastic and have exactly the same shiny  
embossed numbering.


I've typed my PIN into them maybe 50 times and I can't see any wear at  
all.[1]


The cards though... the 'keys' aren't made of rubber, there's almost no  
give in them at all and non-reflective plastic (which is what these things  
look like) does have a tendency to 'shine'.


Footnote

--------

1. In the PINsentry machines, you have to use other number keys than just  
your PIN in order, for instance, to enter account numbers and transfer  
ammounts. I think that may be sufficient to even the wear out on them.

-- 
-blj-