Porn blocks in Iran break the internet across the world

The country’s strange technique was meant to stop people watching adult videos, but had a much broader effect than intended

(AFP/Getty)

Iran introduced blocks on pornography so aggressive that they broke the internet around the world.

The country's censorship laws on adult websites are infamously stringent, and require access pornographic websites to be cut off. But last week the state internet provider did so not only for those in Iran but for people across the world – as far away as Russia and Hong Kong.

The strange ban was the result of the way that the internet provider cut off access to those sites. It did so using some of the basic mechanisms of the web – not just stopping people in Iran accessing the websites, but changing the directions that power the internet so that nobody could.

Using a trick known as BGP hacking, the Iranian internet provider changed what is in effect the roadsigns of the internet. It pointed anyone looking for any of a list of 256 to the wrong place – meaning that their computer wouldn't be able to find the proper way to those pages.

But the technique means that any other computer will see the same fake route as an easy shortcut to the website it is looking for. That applies not only to computers in Iran, but anyone close enough to be using the same directions – and that included major internet companies like India’s Bharti Airtel, Russia’s RETN, Indonesia’s Telekomunikasi and Hong Kong’s Hutchison, according to The Verge.

Usually, such techniques are not used in Iran or elsewhere – internet providers tend to use more efficient and less unwieldy techniques, which don't lead to the kind of results seen this week. It isn't clear why Iran moved towards using the strange bans.

Bans on internet pornography are growing in use across the world, with countries including the UK looking at ways of limiting and censoring the websites that their internet users can access.