I think it is a reasonable thing to say to users when the certificate is
issued to them:
We will NOT EVER ask you for any other authentication information on our
web site. This certificate is the only way that you authenticate to us
on the Internet. If you ever see our bank web site asking you for your
authentication information, please report it immediately to our security
department.
But how will it be said? On paper? It will be ignored. Over the phone?
Forgotten. In person ? Probably ignored. Nailed to their forehead ?
...
Ah yes, of course. Then we face the problem of users having lots of
these little devices ... or losing them, or insecure use (leave in
slot), etc ...
Well, it is possible for a single token to contain multiple
certificates/private keys, so it does not HAVE to lead to proliferation.
And of course, a number of banks are issuing smart card based credit
cards and debit cards. I wonder how big a leap it would be for the banks
to include a private key on the card, too.
But then you are creating more problems for the poor customer who
loses his card. Not only does he now have to worry about his credit
limit being maxed, but all his savings stolen too...
Then, with a smart card reader, which will become ubiquitous as more and
more banks start using this technique, you simply plug in your credit
card, and you are authenticated.
It should even be possible to enforce good password controls in the
smart card, such as limiting the number of retries, enforcing a password
length, etc. Password reset could possibly even be handled by the ATM's,
if they have access to a PUK.
I would like to think that people would not leave their credit cards in
the slot when they are finished, as they asociate the credit card with
physical security (keep it with me).
And I'd like to think that users would lock their workstations when
they wander around the office, or, or, or ...
The slots would have to beep very annoyingly to remind the user to
take it out (a la ATMs) otherwise they would most definately forget.
Even still, how many people would leave their wallets at their desk (I
do). What about women (not to get sexist here ...:)) but I don't see
them carrying their purse around the office :)
-- Michael
