DNS

So, posting again after ages of leaving this blog empty.

I came up with something quite interesting. The concept is not that new, but this could well be the basis for another AntiCense (one which is not so user-friendly).

I am talking about DNS tunneling - it is possible to tunnel UDP traffic (and for that matter, just about any traffic) through DNS. All it takes is a domain name.

Censoring consists of two parts:

1. Monitoring / Viewing Traffic
2. Preventing / Blocking Traffic

The use of appropriate encryption makes point 1 very difficult. But up to this point it was always difficult to work against point 2. However, I will likely engineer a PoC (proof-of-concept) on this technique which will demonstrate just how difficult it is to block this sort of traffic - after all, the proxies are usually provided by the ISP (DNS servers, in this case).

Of course, those behind HTTP proxies are still going to be unlucky, but you cannot make everybody happy.

If you are interested in more information, contact me.

Proxy List

At http://proxy.org/ you can find a nice, up-to-date list of web proxies, like the ones mentioned above. This is a great source for those looking for available mirrors.

Censorship Circumvention Tutorial

I probably should have added this link straight away when I started this blog, but it is here now anyway:

http://zensur.freerk.com/ - This is a censorship circumvention tutorial. Mirrors:

(quoted from the site itself)

1.3 How to get this file

As you are reading this you actually found this file somewhere. The most updated version you can get here:

European mirror: http://www.zensur.freerk.com/ - (Lambdanet - Erfurt, Germany)
American mirror: http://nocensor.citizenlab.org/ - (University of Toronto - Toronto, Canada)
Asian/Pacific mirror: http://blocks.orcon.net.nz/ - (Orcon ISP - Auckland, New Zealand)

SSL mirror: https://secure.sslpowered.com/bpass/ (Netfirms, Toronto, Canada) and https://ssl-account.com/zensur.freerk.com/
Dynamic IP mirror: http://cship.no-ip.org:82/ (Road Runner Cable - Tampa, FL, USA)

eMail autoresponder: index.htm@zensur.freerk.com (just send an empty email, you will instantly get this text as plain HTML in return)

Google Cache: http://www.google.com/search?q=cache:www.zensur.freerk.com/ - (maybe some days old)

Publishing Information using Usenet

A useful tool when it comes to publishing information is usenet. This is basically an online news server. There are lots and lots of usenet servers on the Internet, and many of them duplicate posts from one another.

To the publisher this means that information is very difficult to censor. When something is posted on a usenet server, it will be duplicated among hundreds of other usenet servers. To remove a post, it has to be removed from usenet servers all over the world - subpoenas have to be gotten for each of these servers, some of which are very difficult to even find.

But to successfully publish information on usenet, one has to post it to at least one server - which can be difficult in certain countries.

Anyway, I won't describe how to do this here. Instead, I will post some links for you to look at:
A useful tool when it comes to publishing information is usenet. This is basically an online news server. There are lots and lots of usenet servers on the Internet, and many of them duplicate posts from one another.

To the publisher this means that information is very difficult to censor. When something is posted on a usenet server, it will be duplicated among hundreds of other usenet servers. To remove a post, it has to be removed from usenet servers all over the world - subpoenas have to be gotten for each of these servers, some of which are very difficult to even find.

But to successfully publish information on usenet, one has to post it to at least one server - which can be difficult in certain countries.

Anyway, I won't describe how to do this here. Instead, I will post some links for you to look at:

• http://tgos.org/newbie/
• http://www.ocf.berkeley.edu/help/usenet/

Ok, that's two ("some"), but I think they will be useful enough.

CECID Updated!

As blinken commented on my last post, the CECID web site is now updated. http://cecid.sourceforge.net/ now redirects to http://cecid.labyrinthdata.net.au/.

The mirrors list (http://cecid.labyrinthdata.net.au/mirrors.php) is working again.

Unfortunately, blinken has stopped development of CECID. I found it very useful since it is PHP-based and almost any "free web space" provider allows PHP. Maybe somebody will fork, we shall see.

Web Proxies

Right, another post:

Web proxies are a very nice way to access censored web sites. They do not require local installation and so many of them exist that it is near impossible to "block" them all.

I will describe two types of web proxies today:

1. CECID
2. CGIProxy

1. CECID

The CEnsorship CIrcumvention Device is a PHP-based web proxy. A list of CECID scripts can be found at http://cecid.sourceforge.net/mirrors.php, although that list isn't necessarily very useful.

The main difficulty in finding CECID scripts is to find one working one - the entry point. Once you have found a single script which is functional, it is easy to find more. The URL which you are using probably ends in something like cecid.php(?...). This is the name of the actual script itself. You can access a list of other scripts by changing this to cecid.php?stats=1. When you look down the page, you will find a list of scripts to try out.

To use CECID, visit the script (cecid.php, without a question mark or anything behind that) and enter the URL which you would like to visit into the box. Press enter and enjoy!

2. CGIProxy

CGIProxy is, as the name suggests, as web proxy script written using CGI (this is just a technical detail). A list of mirrors is not as easily available, but please feel free to look below for information regarding this.

Using CGIProxy is similar to CECID, most things should be obvious.

Finding a Script

The most difficult thing you will encounter in using a web proxy script is finding one to use. Many scripts are already blocked by ccensorship software such as SurfControl, so it can be extremely difficult to find a web proxy. This is intended to provide information regarding that issue.

One place you can go (if you can go there) is http://zensur.freerk.com/. Freerk is kind enough to provide a list of scripts at this URL. Look at 4.5 for more information.
(NOTE: if you cannot visit the URL above, a mirror can be found at http://blocks.orcon.net.nz/).

There are more ways of finding these scripts of course, but I will hold back with this, since I would be making it easy for censors to find them. I may post information later.

Tor

Located at http://tor.eff.org/ is a project created by members of the Electronic Frontier Foundation (an organization fighting for digital rights).

It allows anonymous use of the Internet, hiding one's IP (a unique address assigned to a user by their ISP) from accessed servers.

It also allows anonymous hosting of services. This is done through so-called hidden services.

The purpose of this post is not to explain in detail how Tor works or how to use it. For that information, you can simply visit the web site linked to above. I am posting this to encourage support of free speech in the community by running Tor on your computer.

It is easy to get Tor running (even if you don't want to use it yourself) and thereby support the Tor network. To run Tor, do the following:

1. Download Tor from the tor website.
2. Install it if required.
3. Run Tor from your start menu or set it to automatically start with Windows (option during installation).

If you want to run Tor as a Windows NT service (if you don't know what that is, you probably don't want to run it that way), download Winserv and use the following command to install Tor:

winserv install Tor -start auto

You can then start Tor like any other NT service. The service will be named "Tor".