two factor authentication

[William Ahern]

On Tue, Jul 25, 2006 at 09:14:42PM +0000, Jefferson Ogata wrote:
> On 2006-07-25 21:06, William Ahern wrote:
> > ATM cards are not like smart cards wrt to a very critical characteristic,
> > you cannot "copy" a smart card.
> 
> > Well, a smart card
> > is a computer you keep in your pocket or at your side 24/7, and even more
> > it's a computer that is, in all practicality, impossible to install malware
> > on.
> 
> The thing to remember is that those assertions are true in theory, but
> because of the closed nature of a smartcard, such assertions are
> actually much harder to test than equivalent assertions about other systems.
> 
> Smartcards are a bit like closed DRE voting machines in this respect.
> And just as in election systems, the target market--high-security
> applications--is inherently one which someone could benefit greatly by
> exploiting.

I disagree. IBM researchers and others have published how-to's for breaking
smart cards, and the design of smart cards themselves is fairly open.

However, so far the only way to break into a smart card inevitably destroys
the card itself.

That's not to say it's impossible to get the private key w/o destroying the
card (maybe through design flaws by some of the many manufacturers--maybe
I'm wrong about "many"), but the problem looks pretty darn hard, and it's
the intractibility of the problem which limits all or most attacks.
Certainly rendering impossible many classes of attacks used today against
common secrecy mechanisms and devices.

Actually, one of the issues comes down to software versus hardware. W/o a
hardware token that will not or cannot disclose it's private information (as
opposed to common finger print scanners, for instance, which must send the
data to software running on external devices for processing), inevitably
somebody will write software to automate attacks. That's what software does
best, automating sophisticated tasks.