You’ve probably heard of the Great Firewall of China, the virtual fortification that allows the Chinese government to monitor and restrict internet traffic to and from the world’s most populous nation. Well, the cyber-security chief of the UK Government Communication Headquarters (GCHQ) has suggested early plans for what sounds rather like a “Great British Firewall”. Privacy groups immediately sounded the alarm that it might pose a risk to freedom of speech, and offer the potential for Britain’s secret services to get up to no good. So what exactly is GCHQ proposing and should we be worried?
Firewalls are standard tools for computer defence. They are essentially filters which can control what traffic enters and leaves a network. You are probably protected by a firewall right now, at your workplace or at home, that runs either on your computer’s operating system or on the hardware that provides your connection to the internet.
A firewall can be configured to reject certain types of traffic deemed undesirable or potentially harmful. This might be a connection request from an untrustworthy source, such as a web address known to harbour hackers or spammers, for example. Or it could block a file that looks like it might contain a computer virus or other malware. While deflecting this sort of undesirable traffic the firewall allows standard traffic such as web browsing and email to pass through.