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Analyzer是GreatFire的第一个项目,在2011年上线后,它一如以往的为大家提供测试服务直至今日。现在,我们做了一个新的项目叫做"Blocky",欢迎大家试用这个全新的版本!如果您对此有任何意见和建议,请发送邮件到support@greatfire.org
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星期六, 2月 04, 2012

Is the Great Firewall blocking outgoing traffic only?

Connection reset. That is the famous response shown to web users in China when they are trying to access one of the over 2600 websites and searches that have been blocked by the authorities. But what is actually blocked and what is causing the connection disruption? Our research suggests that the Great Firewall (GFW) does not filter any incoming data, but only the outgoing traffic.

It is often said that the GFW imposes three types of censorship. The first one is DNS poisoning. For example, this happens when users in China attempt to access facebook.com. The name servers return an incorrect IP address which doesn't work. The browser tries to load the website for a certain period of time until the whole exercise 'times out'.

The second type of censorship is keyword-based. For example, if one tries to search on Google for facebook, freedom  or some of the other 250+ blocked searches, the connection is immediately reset. In addition, users are restricted from accessing any content on the same website for a minute or so.

The third type is supposed to be content based. Regardless of what was searched for or the address that was entered, if the content contains certain keywords, it is supposed to be blocked. This is where our findings become relevant. They suggest that the GFW doesn't interfere at all with the content that is sent back to the web user in China.

星期二, 1月 03, 2012

Gmail is getting faster but still not as fast as dial-up

Many in China have complained that Gmail is so slow that it is almost impossible to use (see our original story from March 2011 - Gmail now 45 times slower than QQ). We have continued to gather data on the Gmail situaiton in light of Google's continued operation in China. With more data we can now show how the situation has developed since March. The results are clear in this chart:

All foreign webmail providers are considerably slower than domestic competitors (QQ is included for comparison). Out of Gmail, Hotmail and Yahoo, a distressed Yahoo, whose local partner in China is Alibaba, is consistently the fastest free foreign email provider. Hotmail has at times challenged Gmail to a race to the bottom. Using the same comparison as in March, Gmail is now only 9 times slower than QQ and has seen a considerable improvement in speed since September.

One way to put the speed of Gmail into perspective is to compare today's access speed with old dial-up modems, for those that remember. In the 1990s, they provided speeds up to 56 kbps, or roughly 7000 bytes per second. That is considerably faster than the average speed of either Gmail or Hotmail, when accessed from within China in 2011.

Apart from speed, the main problem with Gmail in China is instability. Rather than blocking the service outright, it seems that the authorities have chosen to impose occasional, random outages. Looking back over the year (from March onwards), we can see the following:

Surfing the Internet in China slower on Sundays

Browsing websites is often a slow and frustrating experience in China. Apart from blocking over 2600 websites and searches, the Great Firewall also imposes a serious bottleneck on speed. There have been rumors that the Internet is especially slow on Sundays. Analyzing more than 80,000 tests executed by our system from March to November this year, our data seems to confirm this suspicion.

The tests consist of downloading the front page of each of the world's 500 most popular websites, as defined by Alexa. Apart from aberrations in March and June, download speeds on Sundays have consistently been between 8 and 25% slower than the average of the other days of the week. Here's the full test data summary (all speeds in bytes/second):

星期五, 12月 16, 2011

乌坎在微博上被屏蔽

BBC昨天的报道称"乌坎",一座正在进行大型反征地游行的南方小镇的名字,已经被加入了微博的搜索屏蔽词汇

(China protest in Guangdong's Wukan 'vanishes from web'). 

我们的系统尚未自动监控新浪微博的搜索屏蔽词汇(我们现在有微博监测了),不过以下是手工测试的结果:
KeywordStatus
乌坎Blocked
WukanBlocked
WKNot blocked
禄丰Not blocked
LufengNot blocked

当尝试搜索一个被屏蔽的关键词时,微博会给出这样的提示:

根据相关法律法规和政策,“wukan”搜索结果未予显示

但是,在微博之外,乌坎这样的关键词们却并没有在Google或者Wikipedia(包括中文版和英文版)上被封锁。我们的系统在不断跟踪他们的状态,就显示在本页右上角。

只在微博上屏蔽这些词汇也许验证了在有关部门眼中微博相比其他媒介具有特殊的重要性。

星期五, 10月 14, 2011

所有WordPress博客在中国被封锁

WordPress.com, 有名的博客提供商在本周被中国屏蔽。

浏览以下建立在wordpress上的博客 (使用我们提供的搜索栏搜索“wordpress”) 显示

以前被封锁的博客: 7个 共21个 (33%).

现在被封锁的博客: 21个 共21个 (100%).

wordpress.com 也被封锁。 有趣的是 wordpress.org 也没有被封锁。因此,中国的用户仍然可以下载 WordPress 软件, 却必须将此将博客建立在其他的地方。

星期一, 10月 10, 2011

We've moved to greatfire.org

Today we've moved to a new domain: https://greatfire.org. Here are some notes on what this means:

We're not blocked in China

Though it may only be a question of time until this changes, for now our website is accessible in China without a VPN or proxy. Back in March, before we were blocked, we started getting traffic from Weibo (the biggest Chinese equivalent to Twitter) and we hope to be able to inform Chinese users on the extent of online censorship here.

We're on a secure server

Notice that our address starts with HTTPS. This means that all traffic between your browser and our server is encrypted. And the result of this encryption is that it is impossible for the Great Firewall to intercept the traffic, if you're viewing our website from China. HTTPS is a term to remember, it's the biggest reason why the authorities have semi-blocked access to GMail here.

.org as in non-profit

We are a non-profit organization which is now reflected in our name. Our mission is to bring transparency to online censorship in China. We do need your help to make our operations sustainable.

Feedback is very welcome, as always.

星期二, 8月 23, 2011

How our tests are done

We have been detecting which websites are blocked in China since February this year. Using our tool and contributions from our visitors, we've created the most complete database anywhere of what's blocked by the so-called Great Firewall of China, including 2200+ blocked websites and 200+ blocked searches. But how accurate is our data?

When a website is tested, it's always done by comparing the results of trying to access it from A) a computer outside China and B) a computer inside China. This way, a website that is simply not working is not labelled as blocked. A website that works when accessed outside of China but fails when tested from inside China, on the other hand, will be labelled as blocked.

This makes our data more accurate, but not perfect. Another difficulty is that the Great Firewall often changes temporarily. A given website that was previously accessible may be blocked for, say, 20 minutes. The opposite is also true. Blocked websites are sometimes temporarily accessible. Examples include Facebook (March 28, April 25) and YouTube (July 31, Aug 15 etc).

To tackle this particular challenge, our scripts always re-run testing of a website once more, after it's status has changed. In most cases, temporary changes are quickly detected and the websites are labelled correctly again. In some cases, however, if the change lasts somewhat longer, it may take up to a week for our system to re-label the website correctly. So, for example, Paypal was tested to be blocked twice on Aug 22. It's now accessible again. But it will take several days before our system automatically tests it again. Meanwhile, it's labelled as blocked.

星期四, 5月 19, 2011

Who is protecting the VPNs?

In recent days news has spread that China is cracking down on VPN use (Guardian, Global Voices). Chinese internet users, particularly those in universities, are finding it increasingly difficult to make use of VPNs to circumvent online censorship and access blocked websites. This seems to be a continuation of the increased censorship witnessed this year, including temporary blocks of GMail and LinkedIn.

While important, this development leaves an obvious question unanswered: Why do the authorities not block access to the main websites of the major VPN providers? Each serious provider offers access to a number of servers around the world and blocking actual usage of these is somewhat complicated. The main websites, however, could be blocked in an instant. After all, the Great Firewall has no problem constantly blocking other websites such as Youtube and Facebook.

There are three apparent possibilites. The first is incompetence. The authorities might simply not be aware of the VPN providers that are not blocked. This seems unlikely for two reasons. First, all it takes is a Google search of, say, "VPN China". Blocking the top 10 results would go a long way to making VPN access in China more difficult. Second, some providers, such as StrongVPN, are in fact temporarily blocked from time to time.

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