It is fair to say that China today has the world's most strict and sophisticated Internet censorship rules. Since 1996, when the first of three governmental regulations on Internet usage was passed, the central government authorities of the Celestial Empire have done much to tighten the state’s grip over the Internet. Long-sought and perceived by some as a way to get round news information filtering, web access has brought China and its netizens only a tiny fraction of what can be called freedom.
Great Firewall
The Chinese government tried to supervise and filter all content from the very first day the Internet arrived in mainland China. Still, tight internal control over it became possible only when the Golden Shield Project started functioning as a part of the Great Firewall of China.
The Great Firewall of China was first used as a term in 1997 to describe a set of legislative initiatives and technologies implemented by the Chinese authorities to regulate the Internet within the country’s borders. The government attributed such a policy to the need for the country to protect itself from “harmful information.”
Internet Censorship in 2019
With every passing year, the massive scale of information control in China has been retained and even expanded. In fact, the Internet freedom index in the country reached its minimum in 2019 with some of the content and activities being censored even more than before. Online platforms focusing on curated topics such as entertainment, dating, and celebrity gossips faced a new wave of limitations. Subjects, like economics, that were previously far off the scope also underwent a certain level of sanitization. Substantially increased the risks of being arrested or imprisoned due to accessing or sharing forbidden content.
Blocking Methods
As of 2019, Chinese internet service providers use different methods of content access blocking. The most common of them are presented below.
IP range ban
The Great Firewall is known to be using a blacklist of IP address ranges that are automatically dropped if requested. The list includes ranges used by many popular, high-traffic websites such as Facebook which therefore can’t be accessed from China.
DNS filtering
Another method of restricting users from browsing unacceptable websites is DNS filtering and redirection. The way this approach is applied seems to be completely keyword-centric with banned keywords being shared between numerous Chinese internet service providers. When trying to type in and open a blocked domain, the GFC injects a fake DNS ( that’s also known as spoofing) and redirects users to a random black hole IP address disrupting any unwanted connection.
URL filtering
Except for DNS filtering, the Great Firewall uses one more keyword-centric mechanism that analyzes websites and denies access to them based on certain keyword patterns. The GFC utilizes transparent proxies to scan each individual URL, inspecting such components as the host header, webpage content, and Server Name Indication. If the Firewall decides that the page has to be blocked, it returns a 403 error or prevents the page from loading.
Traffic analysis
It’s been found that the implementation of machine learning algorithms allows the Great Firewall of China to analyze and block web traffic by evaluating its behavior. During the process, each destination IP is assigned a score that represents how trustworthy a connection is to the Chinese Firewall. If the GFC finds the connection to be suspicious, it slows it down to a possible minimum, which results in request expiration.
Other blocking methods
Other methods of content blocking include but are not limited to the man-in-the-middle attacks, packet forging, and filtering of specific internet protocols, mainly IMAP4, POP3, and SMTP.
Ways to Lift Internet Censorship in China
The problem of bypassing government-imposed Internet restrictions has long been concerning the online community of China. For today, users generally rely on the following ways to access restricted content.
Virtual private network
Virtual private networks are very popular among Chinese netizens as they allow to bypass the Chinese Firewall and access any required content. Besides, they also change the user's IP location and provide a high-level of traffic encryption so that ISPs couldn’t snoop on the connection. Though not all VPNs are good at bypassing internet censorship restrictions in China, some of them, like SwitchVPN, have very advanced obfuscation technologies and have proven to work well in the country.
Proxy server
Black-listed websites can also be accessed via a proxy server. To connect to a proxy server, one can install a browser extension or download specialized software. There are a lot of free proxy server lists offering dozens of IPs. Usually, you’ll just need to enter the IP address of your chosen server, it’s port, and hit the connect button. However, it’s worth keeping in mind that a proxy doesn’t cipher your traffic or hide your identity and therefore isn’t very reliable, especially if transparent.
Tor
Though the Great Firewall of China is constantly improved to combat anonymity networks such as Tor, it hasn’t yet achieved that degree of sophistication to block it completely. During recent years, the GFC made a giant leap towards detection of Tor-enabled nodes and bridges, which allows it to drop identified Tor-over-the-Internet connections. Even so, many Chinese users report that they can still use Tor with Obfs4 proxies.
Mirror websites
Some companies use mirror websites, granting their users the ability to access the content from China. Basically, the mirror website is a replica of the original website which uses a different URL. Some of the famous websites that implemented mirroring are Wikipedia, WikiLeaks, and Facebook.
