Re: Bringing Tahoe ideas to HTTP

2009-09-18 Thread Peter Gutmann
Alexandre Dulaunoy adu...@gmail.com writes:

On the same idea, there is an expired Internet-Draft called Link
Fingerprints :
http://www.potaroo.net/ietf/idref/draft-lee-uri-linkfingerprints/

Although the draft has expired, the concept lives on in various tools.  For
example DownThemAll for Firefox supports this.  There was some discussion
about including it into FF3, but then the draft was dropped and the FF support
never appeared, does anyone know what happened?

(The cynic in me would say it's such a simple, straightforward, easy-to-
implement idea, of course it'll never be adopted when there are things like EV
certs to be pushed instead, but who knows...).

Peter.

-
The Cryptography Mailing List
Unsubscribe by sending unsubscribe cryptography to majord...@metzdowd.com


Re: Bringing Tahoe ideas to HTTP

2009-09-18 Thread Alexandre Dulaunoy
On Fri, Sep 18, 2009 at 6:27 AM, Peter Gutmann
pgut...@cs.auckland.ac.nz wrote:

 Although the draft has expired, the concept lives on in various tools.  For
 example DownThemAll for Firefox supports this.  There was some discussion
 about including it into FF3, but then the draft was dropped and the FF support
 never appeared, does anyone know what happened?

It was a SoC project within Mozilla but seeing the following discussion :

https://bugzilla.mozilla.org/show_bug.cgi?id=377245

The state looks a bit unclear to me...

 (The cynic in me would say it's such a simple, straightforward, easy-to-
 implement idea, of course it'll never be adopted when there are things like EV
 certs to be pushed instead, but who knows...).

mode type=cynic
Right... When I see the EV audit process[1], it looks to me like PCI DSS without
the technical aspect...
/mode

[1] http://cabforum.org/WebTrustAuditGuidelines.pdf

-- 
--   Alexandre Dulaunoy (adulau) -- http://www.foo.be/
-- http://www.foo.be/cgi-bin/wiki.pl/Diary
-- Knowledge can create problems, it is not through ignorance
--that we can solve them Isaac Asimov

-
The Cryptography Mailing List
Unsubscribe by sending unsubscribe cryptography to majord...@metzdowd.com


Re: Bringing Tahoe ideas to HTTP

2009-09-17 Thread Alexandre Dulaunoy
On Thu, Aug 27, 2009 at 11:57 PM, Brian Warner war...@lothar.com wrote:

 == Integrity ==

 To start with integrity-checking, we could imagine a firefox plugin that
 validated a PyPI-style #md5= annotation on everything it loads. The rule
 would be that no action would be taken on the downloaded content until
 the hash was verified, and that a hash failure would be treated like a
 404. Or maybe a slightly different error code, to indicate that the
 correct resource is unavailable and that it's a server-side problem, but
 it's because you got the wrong version of the document, rather than the
 document being missing altogether.

On the same idea,
there is an expired Internet-Draft called Link Fingerprints :

http://www.potaroo.net/ietf/idref/draft-lee-uri-linkfingerprints/

I made some experiments around while used as Machine Tag/Triple Tag[1] :

http://www.foo.be/cgi-bin/wiki.pl/MachineTagLinkFingerprint

to have an extension with OpenPGP detached signature.

Another potential use, it's to benefit from the number of users
checking the integrity and contribute back the computed
value into a tagging system like del.icio.us or any other
collaborative bookmarking.

I especially like the Firefox (or wget,curl) extension that
could compute the hash value and check it against various
contributed hashes. That could give a kind of confidence level
regarding the integrity of the file and its corresponding URL/URI.

Just some ideas,

adulau

[1] http://www.foo.be/cgi-bin/wiki.pl/MachineTag

-- 
--   Alexandre Dulaunoy (adulau) -- http://www.foo.be/
-- http://www.foo.be/cgi-bin/wiki.pl/Diary
-- Knowledge can create problems, it is not through ignorance
--that we can solve them Isaac Asimov

-
The Cryptography Mailing List
Unsubscribe by sending unsubscribe cryptography to majord...@metzdowd.com


Re: Bringing Tahoe ideas to HTTP

2009-09-16 Thread Ivan Krstić

On Sep 15, 2009, at 4:12 PM, James A. Donald wrote:
The ideas used in Tahoe are useful tools that can be used to solve  
important problems.



Yes, and I'd be happy to opine on that as soon as someone told me what  
those important problems are.


--
Ivan Krstić krs...@solarsail.hcs.harvard.edu | http://radian.org

-
The Cryptography Mailing List
Unsubscribe by sending unsubscribe cryptography to majord...@metzdowd.com


Re: Bringing Tahoe ideas to HTTP

2009-09-15 Thread Ivan Krstić

On Aug 27, 2009, at 2:57 PM, Brian Warner wrote:
I've no idea how hard it would be to write this sort of plugin. But  
I'm

pretty sure it's feasible, as would be the site-building tools. If
firefox had this built-in, and web authors used it, what sorts of
vulnerabilities would go away? What sorts of new applications could we
build that would take advantage of this kind of security?


What you're proposing amounts to a great deal of complex and  
complicated cryptography. If it were implemented tomorrow, it would  
take years for the most serious of implementation errors to get weeded  
out, and some years thereafter for proper interoperability in corner  
cases. In the meantime, mobile device makers would track you down for  
the express purpose of breaking into your house at night to pee in  
your Cheerios, as retaliation for making them explain to their  
customers why their mobile web browsing is either half the speed it  
used to be, or not as secure as on the desktop, with no particularly  
explicable upside.


It bugs the hell out of me when smart, technical people spend time and  
effort devising solutions in search of problems. You need to *start*  
with the sorts of vulnerabilities you want to do away with, or the  
kinds of new applications you can build that current security systems  
don't address, and *then* work your way to solutions that enable those  
use cases.


It's okay to do it in reverse order in the academia, but you seem to  
be talking about real-world systems. And in real-world systems, you  
don't get to play Jeopardy with cryptography.


Cheers,

--
Ivan Krstić krs...@solarsail.hcs.harvard.edu | http://radian.org

-
The Cryptography Mailing List
Unsubscribe by sending unsubscribe cryptography to majord...@metzdowd.com


Re: Bringing Tahoe ideas to HTTP

2009-09-15 Thread James A. Donald

Ivan Krsti  wrote:
What you're proposing amounts to a great deal of complex and complicated 
cryptography. If it were implemented tomorrow, it would take years for 
the most serious of implementation errors to get weeded out, and some 
years thereafter for proper interoperability in corner cases. In the 
meantime, mobile device makers would track you down for the express 
purpose of breaking into your house at night to pee in your Cheerios, as 
retaliation for making them explain to their customers why their mobile 
web browsing is either half the speed it used to be, or not as secure as 
on the desktop, with no particularly explicable upside.


The ideas used in Tahoe are useful tools that can be used to solve 
important problems.


It is true that just dumping them on end users and hoping that end users 
will use them correctly to solve important problems will fail


It is our job to apply these tools, not the end user's job, the hard 
part being user interface architecture, rather than cryptography protocols.


Yurls are one example of an idea for a user interface wrapping
Tahoe like methods to solve useful problems.

-
The Cryptography Mailing List
Unsubscribe by sending unsubscribe cryptography to majord...@metzdowd.com