[hcs-d] Fwd: New Harvard ID Card Announcement

Joshua Kroll jkroll at fas.harvard.edu
Wed Jul 9 23:45:22 EDT 2008

An obvious choice beyond name and HUID for info on the second strip is
a secret unique ID - a nonce unique to the card which would prevent
existential forgery of the type we saw in the old cards. And there are
plenty of applications where it might not be sensible to have an
RF-emitting and power hungry prox sensor. For example, it would be
useful on vending machines, which might not support such newfangled
gadgetry, or in dining halls.

I think the plan is to go to a tiered security model in which
different applications are secured by different aspects of the card
(this came from our Scott Bradner talk in the spring - if you missed
it, well, now you know what you missed (we also discussed DNSSec, so
it all really comes together)). It would be advantageous for them to
continue to use the unsecured strip for certain things (assuming the
other strip is in fact more secure) on the theory that it segments
attacker classes. Of course, this is somewhat stupid since magstripe
is magstripe and phasing out the less secure strip is almost certainly
a good idea across the board.

Who wants to be that the 1D barcode on the front has been supplimented
by a 2D barcode? Recall that they can't eliminate the 1D barcode, or
they'd have to replace all of the library hardware.


On Wed, Jul 9, 2008 at 8:38 PM, Keito Uchiyama <keito at hcs.harvard.edu> wrote:
> I also read this e-mail with great interest. Personally, I'm wondering what
> the second, thinner magnetic strip will do; if it's for future use, why
> wouldn't said future uses use the IC card system also? Presumably the second
> strip contains information not in the original strip, but what information
> would it contain besides the HUID or other unique identifier? (Or maybe it
> just means they'll phase out the older strip in later iterations of the
> card, and the newer strip is more secure.)
> Keito U.
> On Jul 10, 2008, at 12:29, Joshua Kroll wrote:
>> This seems worth a discussion. Notably, I'm guessing these use some
>> sort of pseudo-secret easy-to-cryptanalyze cipher like most cards of
>> their ilk. Still, I suppose attacks aren't quite as point-and-click as
>> we observed with the last design. Of course, if they're retaining the
>> legacy magstripe then they're just carrying forward old risks.
>> Any thoughts?
>> Josh
> -----
> Keito Uchiyama
> keito at hcs.harvard.edu

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