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.

We are continously working to improve our system and to increase the accuracy of our data. Meanwhile, please pay attention to the history of tests of any given website you are looking up. That should give you a good idea of whether a website is always blocked, almost always blocked, sometimes blocked or always accessible.

And if you find any other glitches in our system, please let us know. Thanks for your support.

Comments

More Blog Posts

Subscribe to our mailing list
Show content from Blog | Google+ | Twitter | All. Subscribe to our blog using RSS.

Mon, Jan 26, 2015

An Open Letter to Lu Wei and the Cyberspace Administration of China

January 26, 2015

Beijing, China

 

Mr. Lu Wei

Director of the Cyberspace Administration of the People’s Republic of China 中央网络安全和信息化领导小组办公室主任

Director of the State Internet Information Office 国家互联网信息办公室主任

Deputy Director of the Central Propaganda Department of the Chinese Communist Party 中共中央宣传部副部长

Cyberspace Administration of China,

Floor 1, Building 1,

Software Park, Chinese Academy of Sciences,

4 South 4th Street, Zhongguancun,

Beijing, China, 100190

 

Dear Mr. Lu,

On January 22, 2015, the Cyberspace Administration of China (CAC), which is under your direct control, wrote a response to a story we published about an MITM attack on Microsoft. In the post, your colleague, Jiang Jun, labelled our accusations as "groundless" and  "unsupported speculation, a pure slanderous act by overseas anti-China forces".

We at GreatFire.org take great offense to these comments and we will refute them in this letter.

Mon, Jan 19, 2015

Outlook grim - Chinese authorities attack Microsoft

On January 17, we received reports that Microsoft’s email system, Outlook (which was merged with Hotmail in 2013), was subjected to a man-in-the-middle (MITM) attack in China.

The following screenshot shows what happens when a Chinese user accesses Outlook via an email client (in this case, Ice-dove):

We have tested Outlook to verify the attack and have produced the same results. IMAP and SMTP for Outlook were under a MITM attack. Do note however that the web interfaces (https://outlook.com and https://login.live.com/ ) were not affected. The attack lasted for about a day and has now ceased.

This form of attack is especially devious because the warning messages users receive from their email clients are much less noticeable than the warning messages delivered to modern browsers (see screenshot at the end of this post for comparison).

(Sample error message from default iPhone mail client)

Fri, Jan 09, 2015

GFW upgrade fail - visitors to blocked sites redirected to porn

In the past, the Chinese authorities’ DNS poisoning system would direct Chinese internet users who were trying to access Facebook, Twitter and other blocked websites (without the use of a circumvention tool) to a set of fake IP addresses that are blocked in China or are non-existent. After waiting for some time, Chinese internet users would receive a timeout message if they were trying to access a blocked site.

However, with the new DNS poisoning system, in addition to those IP addresses used before, the Chinese authorities are using real IP addresses that actually host websites and are accessible in China. For example, https://support.dnspod.cn/Tools/tools/ shows that if a user tries to access Facebook from China, they might instead land on a random web page, e.g. http://178.62.75.99

Below is a screenshot by a Chinese user when he was trying to access our GreatFire.org website which was blocked in China. He was redirected to a goverment site in Korea. In essense, GFW is sending Chinese users to DDOS the Korea government's website.

One Chinese Internet user reported to us that when he tried to access Facebook in China, he was sent to a Russian website, unrelated to Facebook. Another user tweeted that he was redirected to an German adult site when he tried to access a website for a VPN.

某墙你这什么意思,DNS 污染返回给我一个德国工口站的 IP,满屏很黄很暴力弹弹弹(

— nil (@xierch) January 4, 2015

Wed, Dec 31, 2014

CNNIC leadership change coincides with blocking of Gmail

On December 26, 2014, in an announcement posted on their website, a new chairperson for CNNIC was directly appointed by the Cyberspace Administration of China. The announcement of this appointment coincided with the complete blocking of Gmail.

Cyberspace Administration of China (中央网信办) is chaired by Lu Wei, “China’s web doorkeeper”. Lu Wei is also the vice chair of the Central Propaganda Department, according to his official resume.

chair.png

This office is directly responsible for the blocking of Gmail and other websites including Facebook, Twitter and Google.

CNNIC is China’s certification authority and operates the country’s domain name registry. 

What are certificates used for?

Certificates are used primarily to verify the identity of a person or device, authenticate a service, or encrypt files. 

What is a certification authority (CA)?  

Tue, Dec 30, 2014

Gmail completely blocked in China

All Google products in China have been severely disrupted since June of this year and Chinese users have not been able to access Gmail via its web interface since the summer. However, email protocols such as IMAP, SMTP and POP3 had been accessible but are not anymore. These protocols are used in the default email app on iPhone, Microsoft Outlook on PC and many more email clients.

On December 26, GFW started to block large numbers of IP addresses used by Gmail. These IP addresses are used by IMAP/SMTP/POP3. Chinese users now have no way of accessing Gmail behind the GFW. Before, they could still send or receive emails via email clients even though Gmail's web interface was not accessible. 

Google's own traffic chart shows a sharp decline of Chinese traffic to Gmail. 

Below is a ping request to the Gmail SMTP server, which is completely inaccessible in China.

 

Subscribe to our blog using RSS.

Comments

inspired a lot from this post am following this blog regularly and found very good for bookmarking thanks admin
happy new year 2015 sms
indian festivals 2015
public holidays 2015
new year 2015 quotes
happy new year 2015
new year 2015 quotes
new year 2015 greeting cards

Add new comment

Filtered HTML

  • Web page addresses and e-mail addresses turn into links automatically.
  • Allowed HTML tags: <a> <em> <strong> <cite> <blockquote> <code> <ul> <ol> <li> <dl> <dt> <dd>
  • Lines and paragraphs break automatically.

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.
By submitting this form, you accept the Mollom privacy policy.