Re: Obfuscated URLs?

[mogulguy@xxxxxxxxx]

--- On Tue, 6/30/09, Freemor <freemor@xxxxxxxxx> wrote:

> Martin Fick <mogulguy@xxxxxxxxx> wrote:
> 
> > In my scenario, the point of hard coding the path is
> > to obfuscate the final URL, ...
> ... But hidden services provide this functionality
> already. 

They provide an obfuscation to a service that you must
run, not an obfuscation of a URL, this is not the same
functionality.  It's like the difference between an
email address and an email server.  Related, but very
different.


> I do understand the potential difficulties in setting up a
> hidden service. But I think it would be easier to automate 
> this aspect of Tor then to write a new protocol. (some 
> more thoughts on this below)

Well, I do not think that you are really giving
hidden services proper consideration.  While setup
is certainly part of the problem, the real kicker,
of course, just like running your own web server,
is running it!  

Maintenance and availability are the real issues 
(hosting).  Even many people with the skills to setup 
their own servers (email, http...) still pay for 
someone to host them (even though they might 
personally admin it remotely).  So the biggest 
barrier is hosting, not setup.  Hosting requires the 
publisher to be permanently active, to have a PC 
always connected to the internet, and to personally 
be linked to the content.  The last part is not 
just an issue of anonymity, suppose that my identity 
is already known, how could I ever host content that
someone wants to censor without the risk of being
raided (and the content thus censored) since my 
identity is already known?


The alternative, remote hosting anonymously is 
hard, as soon as you add payment to the deal, it adds
a whole new level of risk to blowing you or your
hosts anonymity, again making censorship more
likely.


Risks aside, if you look at non-tor stuff, how 
many individuals are willing to run their own email 
server, web server?  Very few.  Why would adding an 
extra layer (tor) to the mix, even if setup became 
much easier, suddenly make people more likely to host 
their own server?  Of course, it wouldn't.  This 
means your are starting with a too small pool
of potential personal hidden service hosts in the 
first place.  

However, how many people have email accounts 
(virtually everybody)?  How many are subscribed to 
some forum, or internet group, or blogging site
with some mechanism to publish to free accounts?  
Not quite as many as the people with email 
accounts, but quite a large number nevertheless.
These are the people that this targets as a 
potential publishing base.  This number is much 
higher than those who run personal web servers.  
This is an entirely different "demographic" than 
those running hidden services.

Hidden services are a genius hack, they provide
interactivity, something all the other censor free
systems do not.  But, interactivity is not always
needed.  Why force a mechanism designed for dynamic
content (and thus more difficult and riskier to 
implement) onto static content when their is an 
easier (*1) and potentially more robust solution 
that tor could implement for static content? 

*1 If indeed it is easy, of course, the devil is 
   in the details. :(


> > As for use cases, I envision that as a simple whistle
> > blower or reporter, I would post my content on various
> 
> [snip]
> 
> OK I now have a clearer idea of what you are wanting to
> do:
>  
> 1). Simple anonymous publishing
> 2). Remove the single point of failure that a hidden
>     service may represent
> 3). Plausable deniability by not having the information
>     hosting tied to you.

Those are some of the things that I am suggesting, yes.
But, I am not limiting it to those.  If you limit your
thinking to that, then, of course, systems that only 
implement that will look appealing. :)


> 1). Someone sets up a hidden service that automatically
> re-directs to the content hosted on non-Hidden sites ...

I think you are effectively talking about a hidden
remapping (not redirecting) proxy.  Yes, this would 
work, but it is not a "good" solution.  Again, it 
suffers from the same hosting requirement and does 
not reduce risk much.  Additionally, this would 
require each implementer to come up with their own 
implementation, make bugs and disclosure that more
likely (not peer reviewed...)


> 2.) GnuNet may be much better suited to what you are
> looking to do. It already has a lot of these features 
> (see http://gnunet.org ) Once you inserted the 
> information into GnuNet you could share the hash for 
> it in as many open sites as you wanted. 

Thanks for the link, I will investigate more.  But,
again, this looks like a distributed storage 
mechanism, not a URL obfuscator.  It is useful and
likely better at doing some of the things that 
Obfuscated URLs could do, but not all of them.  

What I am proposing does not push the content into 
the tor system as most distributed storage systems 
do.  It is an access, not a storage method.

And, of course, I am proposing using tor for my
purposes, I do not want to add another system to
my arsenal.  As soon as you do, it becomes very
complicated to work with 2, 3... systems 
simultaneously.  

As a resource contributor, do I contribute to 
tor, to freenet, to gnunet, to offsystem...?  
Each one of these systems that I contribute to 
takes bandwidth from the other.  This is less 
than ideal.  I believe in many of the objectives 
of many of these systems and dream of a unified
way to achieve and contribute to them all.

Fragmentation has its advantages, particularly
during the research phases.  tor is maturer
than most technologies, but eventually many of
the other systems will implement more and more
common functionality.  If they can do more 
than tor, even if they are not quite as good
at tor's specialty, eventually they might
obsolete tor and everyone will suffer since we
will be using sub par implementations.  Tor
needs to continue getting better at what it is
good at, but if it can also expand its 
capabilities it will likely help expand its 
user, contributor, and developer bases also.



> As for making the content password protected GnuPG 
> would work wonders for this (prior to insertion of 
> course) 

Yes, in fact, I would suggest that documents be store
as .pgps at the real location.  But to be clear, the
intent of the encryption that I was talking about was
to make the obfuscation better, not to control access.  
In other words, it prevents someone from guessing the 
location of the obfuscated URL and seeing if their 
guess is correct by attempting to compare the data
retrieve via the obfuscated URL and via going directly
to their guessed location.  Obviously they can still
compare file sizes...

One additional reason that storing documents as pgps 
would be nice is because then the documents do not 
appear to be tor specific documents, they do not 
shout: "here is an obfuscated URL document!" :)

I hope that some of this makes more sense, cheers,

-Martin