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The CA system is spectacularly broken - can the TAG help?

From: Harry Halpin <hhalpin@ibiblio.org>
Date: Tue, 20 Dec 2011 00:44:34 +0100
Message-ID: <CAE1ny+7s2Xjugh=bAjnNaBnwPpHFWZY1=siEQ8yyVf=MB2qsTw@mail.gmail.com>
To: www-tag@w3.org
While I understand the CA system is somewhat outside your usual remit,
let me add this to your pile of woes. I'm doing this because 1) the
system has so stunningly came apart at the seams last year that it
seems all parties involved in the Web (ISOC, W3C, etc.) should be
actively looking at this issue and 2) there are now three different
proposals for fixing this.

There's currently a giant gaping security issue on the Web, namely
that the it's quite easy to fake the root certificates of a CA and so
compromise  TLS connections - and thus most high-value transactions on
the Web in a way that is *very* hard to detect. For a detailed
explanation of the problem, Moxie of Whisper Systems has an excellent
video [1]. There's been a number of very high-profile compromises,
such as the Diginotar [2] and Comodo attacks [3]. Overall, probably
problem #1 for security on the Web. It undermines all financial
transactions on the Web - I'd bet money Paypal stays awake at night
thinking about this. It's also a life and death situation for human
rights activists in Syria, Iran, and elsewhere - who may not stay
awake another night if the cert for their Gmail or Facebook account is
faked.

Now, over the last weeks I've seen about 3 different proposals that
are quite serious:

1) Google's Proposal (Ben Laurie and Adam Langsley): Basically make a
public audit log of registered certs, and then the client/domain
owners can check their certs versus that log. That probably has some
browser component for checking all of this [5].

2) Sovereign Key proposal from EFF (Peter Eckersley): Similar to
Google's proposal but more complex, uses an audit log of a "Sovereign
Key" rather than certs [4]

3) Convergence Proposal from Whisper Systems/Twitter (Moxie
Marlinspike): Features a more decentralized CA-like system with
user-based "trust agility" where users can choose which CA-like
"notary" to trust via browser [6]

At TPAC, I talked to some of the browser team folks about this,
everyone agreed the CA/Browser Forum is dysfunctional (i.e. a front
for the current broken CA system) and they would be happy to see W3C
or someone move in this space [6]. Google notes "We now have an
outline of the basic idea and will be continuing to flesh it out in
the coming months, hopefully in conjunction with other browser
vendors." [5]

So maybe time for W3C to move? While I understand the TAG only makes
"findings", I suggest that given the overlap between the Google and
EFF proposal, I'm pretty sure there's a solution space going on here
even if it's outside of the TAG's expertise, and that solution space
will probably involve - browsers, and interaction with the CA/Browser
Forum.. Sounds like it's time for W3C to make a move. I'd do an
analysis of the topic, but also suggest that this problem is big
enough to warrant getting folks together on ASAP.

Who: I'd suggest that we return to the idea of hosting a workshop on
this topic, and since it's a large topic, I suggest W3C co-host with
the CA/Browser forum and maybe ISOC/IAB.
When: Soon as possible.

[1]http://www.youtube.com/watch?v=Z7Wl2FW2TcA
[2]http://www.guardian.co.uk/technology/2011/sep/05/diginotar-certificate-hack-cyberwar
[3]http://news.cnet.com/8301-1009_3-20050503-83.html
[4]https://www.eff.org/deeplinks/2011/11/sovereign-keys-proposal-make-https-and-email-more-secure
[5]http://www.imperialviolet.org/2011/11/29/certtransparency.html
[6]http://convergence.io/
Received on Monday, 19 December 2011 23:45:11 GMT

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