The subject of Internet censorship is an odd one for some countries, but it is still prevalent in many countries, causing problems for many products and services. But when did it all begin, and how has it gone so far?

The first main internet censorship was initiated in 1998, with china releasing the Golden Shield, later called "The Great Firewall."

But what was The Great Firewall? 

Internet censorship in China is carried out through The Great Firewall, which restricts access to foreign websites and slows cross-border traffic. The Great Firewall operates by checking transmission control protocol (TCP) packets for keywords or sensitive words; if the keywords or sensitive words appear in the TCP packets, access will be closed. A Great Firewall will block more links from the same machine if one link is closed. Among these effects are the following: 

• Limiting foreign information access 
• Blocking foreign internet tools (e.g., Google Search, Facebook, Twitter, Wikipedia, and others) and mobile apps
• Requiring foreign companies to conform to domestic regulations.

Consequences

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

Accessing foreign websites is already slower than accessing Chinese ones, and using a VPN to bypass the Great Firewall usually slows the connection even more. Sometimes VPN services or individual connections can stop functioning properly for hours or even days at a time, leading to unexpected drops in productivity.

Businesses must also consider the software and internet services they use in their China offices. Many companies with multiple offices use cloud-based services such as DropBox, Google Documents, and GitHub to share resources across different locations. Because these services do not function normally in China, businesses must determine whether they can be used effectively with a VPN or find an alternative such as Microsoft SharePoint or a Chinese cloud-sharing platform like GoKuai.

Censor technologies

There are multiple ways of internet censoring, such as:

• URL filtering
• IP range ban 
• Packet forging 
• TCP reset attacks 
• And many more.

The Chinese government has used a new censorship technique called Active Probing since 2011. Active probing operates immediately after a VPN request is issued; first, the system runs a DPI (Deep Packet Inspection); when there is more suspicion, the system sends a request to the VPN itself. If that connection is successful, the VPN gets blocked.

Tor, the enemy of The Great Firewall

Researchers with the U.S. Navy started developing onion routing, a method for obscuring the source and destination of internet traffic using a network of nodes that encrypt data packets, creating onion-like layers of anonymity in 1995. Their research forms the basis of the Tor browser, one of the first VPNs to confront The Great Firewall.

Using China's weapon

Reporters Without Borders suspects that countries such as Australia, Cuba, Iran, Vietnam, Zimbabwe, and Belarus have obtained surveillance technology from China.

Since at least 2015, the Russian Roskomnadzor agency has collaborated with Chinese Great Firewall security officials in implementing its data retention and filtering infrastructure.

The outcome

There's a quote by Deng Xiaoping(China's former leader) in the early 1980s: "If you open the window, both fresh air and flies will be blown in."

Because the belief is based on protectionism, governments fear these flies because they think their presence can poison people's beliefs.

According to estimates, in 2013, companies based in Europe and with a branch in China had lost 21.3 billion dollars because of The Great Firewall in China and other reasons such as increasing the labor cost.

The history of censorship on the internet shows that even though this censorship is new, we have always been subject to censorship in newspapers, books, and anywhere information flows. While censorship may temporarily stop movements, it is just a temporary painkiller, not a permanent one.