On Apr 12, 2016, at 5:39 PM, Tony Arcieri <[email protected]> wrote:

> On Tue, Apr 12, 2016 at 8:28 AM, Ron Garret <[email protected]> wrote:
> Some hardware tokens have an input device built in (usually a push button, 
> sometimes a fingerprint sensor) which needs to be activated before the token 
> will operate, but these are still subject to phishing attacks
> 
> Not to rain on your parade, but if you're talking about authentication 
> contexts, U2F solves the phishability problem by deriving domain-separated 
> keys per origin, so it's not possible for an attacker to leverage it for 
> phishing purposes.

This HSM is much more general-purpose than a U2F token.  It could be used as a 
standalone bitcoin wallet a la Trezor.  It can be used to decrypt messages and 
display them on the built-in display so that even an adversary with root 
accesss to your laptop couldn’t read the cleartext.  The firmware doesn’t 
support this yet, but it’s a mere matter of programming :-)

But even U2F tokens can be phished for some value of “phished”.  It’s true that 
you can’t extract the keys, but if an attacker owns your machine and you have a 
U2F token installed, the attacker can log into any site you can log into.  Even 
if the token has a button you need to push to activate it, it’s probably not 
hard to fool most users into pushing the button to authorize an authentication 
for an attacker.

With a display, the token can say, “You are about to authorize…” and describe 
exactly what it is that it is being asked to do so that you know what you’re 
authorizing in a way that an attacker cannot control even with a completely 
compromised client.

rg

_______________________________________________
cryptography mailing list
[email protected]
http://lists.randombit.net/mailman/listinfo/cryptography

Reply via email to