The UK’s new National Cyber Security Centre, a division of Government Communications Headquarters (GCHQ), is due to open this month (October 2016). The centre has been given the task of creating a “cyber force” and being the “authoritative voice on information security in the UK”.

One element of the centre’s defence against cyber attacks being considered is a “national firewall” to block incoming attacks. The idea was outlined by Ciaran Martin, GCHQ’s director general of cyber security, at the Billington CyberSecurity Summit in September 2016.

As well as being used by government agencies to protect themselves, Martin also suggested the national firewall could be used by commercial internet service providers in the UK:

“Finally, we’re exploring a flagship project on scaling up DNS filtering: what better way of providing automated defences at scale than by the major private providers effectively blocking their customers from coming into contact with known malware and bad addresses? Now it’s crucial that all of these economy-wide initiatives are private sector led. The Government does not own or operate the Internet. Consumers must have a choice. Any DNS filtering would have to be opt out based. So addressing privacy concerns and citizen choice is hardwired into our programme.”

When national firewalls are mentioned, China is often the first jurisdiction than comes to mind. Such initiatives can start out with the most laudable of aims “in the national interest”. But over time the scope of what is in the national interest could be broadened to cover internet activities, like gambling, that are deemed not to be “good” for society.

If it is developed for the UK, a national firewall just makes it that bit easier for a future UK government to control the internet traffic its citizens can view.