On Mon, 14 Jul 2008, wrote:

On Jul 14, 11:22 am, Roland Perry wrote:
If the mechanism for permanently disabling a card means they have to
be touched to a gate that would rather follow wouldn't it?

So you think the idea was to disable *some* cards, but the system had a
brainstorm and disabled *all* of them?

That would be my guess - a simple programming mistake caused some
isThisADodgyCard() test always to return true so it killed them all.

I don't know if you can update the firmware in the cards. Do they even
have something to update?

Some simple cards are hardwired with just a couple of numeric registers
to carry values but Oysters will have onboard software because they have
to store a simple database of places and times visited plus there's
encryption going on. Whether that software is in ROM or something
read-write akin to flash that can be updated I dunno. Obviously it has
some sort of R/W memory to store the DB , balance etc anyway.

I thought they were basically just memory, with the chip being a memory
controller, and all the authentication and encryption being done in the
gate. Oyster is based on MIFARE Standard:

http://en.wikipedia.org/wiki/MIFARE

That article isn't outrageously detailed or specific, but taking it
together with the generic article on smart cards, i'd say that Oyster is
basically just memory, with a chip for accessing it and doing some
encryption. I would imagine it doesn't have firmware, BICBW.

tom

--
Let us learn to dream, gentlemen, and then perhaps we will learn the
truth. -- Friedrich Kekule