FWIW, my reading of the OP is that it's stipulated that the user will check for the presence of a valid SSL session (i.e. with in browser visual indicators) before login.
BTW, have been following your work on TACK with great interest.
BTW, have been following your work on TACK with great interest.
The "green" indicator is nice but definitely should not be relied upon to protect the user.
note: i used appsp0t as an example, no idea if its really available to be bought.
Edit: it's not letting me reply to the below comment (probably because this is a new account), but afair most browsers have fixed the IDN problem by checking for "suspicious" characters (characters that look similar to roman glyphs) and forcing the URL to be rendered in the full punycode URL.
Not sure how valid that still is (as the talk is a couple of years old? I only watched it today), but it has to be assumed that a portion of users are going to fall for even a badly mimicked url.
Gotta say the IDN stuff is impressive in how generalised it could be. Terrifying. I'm convinced he's owed the $1,000.
But the parent comment is still valid, there's nothing to stop Moxie registering another domain even note-crypt.com or notecrypt.org or anything like that and the average user will be complacent with that. (same applies for appspot, note-crypt.appspot.com vs notecrypt.appspot.com vs notecrypto.appspot.com)
It only takes a single lapse in checking the domain and they've lost their login details and encryption key to the attacker.
Point is, the JS crypto does not add anything to the situation. All the security is provided by SSL, and once it goes, the JS doesn't help. It just gives the users a fake sense of an additional layer of security, which is dangerous.
Moxie broke the current SSL usage, and therefore, he broke the JS crypto (as he controls the communication channel). He beat the current state of the challenge.
My understanding is that the HTST header would make this attack less useful. But it's still a concern if you used Private Browsing/Incognito. The initial request will still hit a 301 (vulnerable to interception by MITM). I've just verified this with Facebook.com on my machine (Chrome 26, OSX).
I think it's quite fair to expect a user using this kind of site is likely to use Incognito.
I'm actually kind of surprised as I thought Chrome had a standard list of sites that use https only such as Facebook. (Woah.. seems the preload list is TINY http://www.chromium.org/sts )
I like the kind of pinning and preloading that chrome does but it's such a tiny gesture compared to the size of the internet, and nobody else seems to be trying to deploy better security.
Perhaps there could be open whitelists where sites could nominate their sites as 'https only'. Wouldn't even need to be built into the browsers, could just be a thing people do when they launch a clean browser install, hit up https://blahsitelist.com and click a button that fires off https requests to all of those sites which would cache the HTST header? (I've only stumbled on HTST headers today, so I may be overly flamboyant as to their usefulness)
Although, come to think of it, isn't that just basically what the HttpsEverywhere extension does?
So my read is that for this particular challenge there's only one "user", the OP. I read it as he's willing to facilitate the attack by using the site from a hostile network but has specifically said he'll check for a valid SSL session.
So by that interpretation, despite how much I think Moxie deserves another $1k for doing great work in general, it seems an SSL strip attack is unlikely to satisfy the offered terms.
Of course I expect an SSL strip attack would be effective against end users generally.