Sunday, April 11, 2010

Dissecting The Great Firewall Of China

China has always been a subject of legend and mystery, in "Western" (non Asian) culture. Recently, one unique Chinese artifact - the Great Firewall Of China - has become a subject of legend and mystery too. For both bloggers (publishers of both Blogger and other blogs - and of various web sites) and bloggees (readers of both Blogger and other blogs - and of various web sites), and for people inside China and outside, the GFWC is the subject of discussion in both techie and non techie blogs, forums, and web sites.

People inside China wonder
Why can't I see my Blogger blog?
and people outside China wonder
Why can't my readers, inside China, see my blog?
And those are the simple questions.

People inside China, more realistically (and echoing some of the questions seen occasionally in Blogger Help Forum: Something Is Broken) ask
Why can't I see all of my Blogger blogs?
or
Why can I see my Blogger blogs, but not my neighbours Blogger blogs (my FaceBook page, my Tweets, ...)?
and people outside China wonder
Why can't some people inside China see (not see) some of my blogs (my web sites, my FaceBook, my Tweets, ...)?


And these questions are asked, differently, by native Chinese citizens, non Chinese citizens, and visitors to China. And everybody will have different observations, and different questions.

The fact is
  1. The GFWC is not one single filter. It, like other Internet components is complex, and is redundant.
  2. The GFWC is not absolute. It, like other Internet components is lossy. It is subject to both false positives (It blocks some content, some of the time, which it should not block.), and to false negatives (It fails to block some content, some of the time, which it should block.).


Compounding the confusion, we have read that Chinese authorities
  1. Know that the GFWC is not absolute. Some Chinese citizens, some of the time, can access content which the GFWC should filter - were it absolute and 100% reliable.
  2. Don't care that it's not absolute. The Chinese are a pragmatic people, and the authorities depend upon lots of Government approved content available to all Chinese people, to overwhelm the non approved (foreign and internal) content that's sometimes available to some citizens. And there are other censorship techniques which are used, too.


Wikipedia: Golden Shield Project identifies 5 different types of GFWC techniques. Each of the 5 different types will have different characteristics. Capriciousness, False Negative / False Positive Count, Latency - are all consequences of any firewall, and will vary depending upon techniques used.

Remember China is one of the largest countries in the world - both demographically, geographically, and politically. Internet structure will reflect each of those characteristics.

Capitalism in China has been known to cause variations in the GFWC.
During the 2008 Olympic Games, Chinese officials told Internet providers to prepare to unblock access from certain Internet caf├ęs, access jacks in hotel rooms and conference centers where foreigners were expected to work or stay.[7]


The Chinese government knows that its country depends upon tourism dollars. Different areas of the country, which will be more or less visited by foreigners, will have better Internet service, and probably more costly and effective filtering. The effects from the Olympic Games unblocking didn't go away immediately, in every hotel and conference center.

The bottom line here is that anybody who visits China, and anybody who produces a blog or web site and targets Chinese readership, should expect some unavailability varying both place to place, and time to time. Anybody who expects consistent availability, or consistent unavailability, is in for a surprise.

>> Top

1 comment:

Lex Li said...

Before Google Reader is blocked, Chinese citizens can subscribe to Blogger sites. That's how I keep reading this blog. :)