• Welcome to Demakis Technologies! We are waiting to help you!

Understanding the Great Firewall of China

Great Firewall of China

Today, we’re going to talk about the Great Firewall of China (GWF). 

You will learn:

  • What is the Great Firewall of China?
  • How does it work?
  • How it impacts people, business, technology, and the world

So if you want to understand the world’s most sophisticated censorship system, then you’ll enjoy this.

Let’s start. 

What Is the Great Firewall of China?

The Great Firewall of China is a popular term for mainland China’s internet censorship system. Both legislative actions and enforcement technologies are used to regulate and control the country’s internet. 

The Great Firewall blocks foreign websites, apps, social media, VPNs, emails, instant messages, and other online resources considered inappropriate or offensive by authorities. 

china firewall

How Does the Great Firewall Block Content and Access?

China controls the Internet gateways where traffic travels between China and the rest of the Internet. Using a combination of firewalls and proxy servers at these gateways, they can manipulate internet traffic. 

There are several sophisticated ways the Great Firewall blocks content and access to various foreign websites. 

Check them out. 

DNS Poisoning

DNS (Domain Name System) is the technology that links domain names and routes them to the right IP address location. One part of the Chinese Firewall is made of liar DNS servers and DNS hijackers returning incorrect IP addresses. 

For example, if you want to visit Facebook’s website, your computer contacts its DNS servers and asks for the IP address associated with the website. China “poisons” its DNS caches with wrong addresses for websites like Facebook on purpose, making them inaccessible.

Blocking Access to IPs

China’s Great Firewall can also block access to certain IP addresses. Equipped with a blacklist of undesirable IP addresses, routers automatically drop all packets destined to blocked IPs (network black-holing). For instance, this could include the address of a sensitive site like the New York Times, or of a public DNS resolver like Google’s.

Analyzing and Filtering URLs

The GWF of China is made of transparent proxies. These proxies can scan URLs and block connections if they contain sensitive keywords.

According to Harvard Law School research results (2003), when searching for, for example, dissident/democracy sites, of the top 100 sites Google returned, 40 were blocked for a “democracy china” search, while 37 “dissident china” sites were blocked, 32 were

blocked for “freedom china,” and 30 for “justice china.

Inspecting and Filtering Packets

Deep packet inspection (DPI) is a content inspection method that can be used to examine unencrypted packets, looking for sensitive material. DPI uses components from an Intrusion Detection System (IDS).

Filtering routers pass copies of passing traffic to out-of-band devices based on IDS technology. The packets continue on their path freely while IDS technology inspects the copies. The point is to determine whether the content of the packets matches the Chinese government’s blacklist of keywords. 

great firewall

Resetting Connections

After blocking the packets with sensitive content, the Great Firewall will block the connection between both computers for some time. How? By sending a “reset packet” 一practically by lying to both computers that the connection was reset so they can’t talk to each other. 

Blocking VPNs

In late 2012, the GFW of China started trying to block VPNs. VPNs were previously used to bypass the Great Wall. In the same year, companies providing VPN services claimed the Great Firewall of China became able to learn and identify what encrypted VPN traffic looks like and then kills VPN connections. 

The Impact of the GFW of China

It’s no surprise that China has the largest number of Internet users 一 989 million by far. 

The majority of these citizens take no steps to penetrate the Great Firewall. 

With this number of people strictly controlled online, you can only imagine the huge impact of the GFW of China.

Let’s see how this impact reflects. 

#1 Social and Political Impact 

The Chinese government sees censorship as a way to maintain social cohesion by maintaining it as a unified national ideology for as long as possible. 

By keeping Chinese citizens in the dark about other ideologies different from Communism, citizens are less likely to revolt because they are not enticed with alternatives. 

#2 Economic Impact

By blocking international internet companies, the Great Firewall protects domestic industries and companies that may have been too weak to compete with US counterparts. 

That’s how China has grown its own internet giants, such as Tencent, Alibaba, Baidu, etc. 

China is predicted to become the world’s biggest economy by gross domestic product in the next 10 years. 

#3 Impact on Creativity

With no easy access to the ideas of the West, it’s likely that this kind of cultural isolation affects creatives in a big way.

Not only that 一 slow VPNs also cause big headaches for writers, designers, and creatives. 

Understanding the Great Firewall of China

The Takeaway for Your Business

For overseas companies whose core business is not directly affected by the Great Firewall, the effects on productivity and day-to-day operations should be considered. 

Many companies either set up their own corporate VPNs for internal use or subscribe to a corporate VPN package for their China offices, regardless of their industry.

Want to know more?

The Great Firewall of China is generally considered the largest, most extensive, and most advanced cybersecurity system in the world. 

If you want to learn more on the cybersecurity topic, please follow Demakis Technologies and continue reading about it on our blog.

Leave a Reply

Your email address will not be published.

You may use these <abbr title="HyperText Markup Language">HTML</abbr> tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>