The Great Firewall of China

Coincidentally there was an article today on Science Blog about the Great Firewall. So yes like I said yesterday their Firewall is not really effective. But is that surprising considering the amount of resources that would be needed for a reliable censorship ?First a quick reminder on how it is supposed to work:

China takes a different approach by filtering Web content for specific keywords and selectively blocking Web pages […] when the Chinese system detects a banned word in data traveling across the network, it sends a series of three “reset” commands to both the source and the destination.

And this works in a protocol agnostic way, so it may reset your DNS request, HTTP session, etc …

Because it filters ideas rather than specific Web sites, keyword filtering stops people from using proxy servers or “mirror” Web sites to evade censorship.

Encrypted content can’t be filtered, that’s why I previously mentioned Tor which has been “omitted” from the blacklist. Now it would not be that hard to filter the Tor network and web site, but just like Google Reader, they are missing the obvious.

But because it is not completely effective all the time, it probably acts partly by encouraging self-censorship, Barr said. When users within China see that certain words, ideas and concepts are blocked most of the time, they might assume that they should avoid those topics.

I suppose the average Chinese will use a Chinese search engine anyway (Baidu is very famous here) which will have its own politically correct “filters”, and even Google is complying with Chinese censorship … or trying.

In fact the networks in China so reliable that I guess the Chinese hitting a “banned” word would just assume that something went wrong with its connection. Getting a “timeout” error is quiet common, and it is not like they redirect you to a page with flashing warnings.

Overall the Great Firewall is just a source of frustration and lost time. Especially when it get overzealous on blocking content you want to access on a daily basis (like developer blogs for example). It is like having a 5cm wall on your way to work, you may trip on it if you don’t pay attention, but it is barely preventing you to do anything. (another analogy would be the lake wall in the Simpson movie, but i can’t get a pic right now).


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