Internet black out: could it happen?
Chaos in the streets as traffic lights fail, fistfights over dwindling supplies of petrol, smashed windows and empty shelves at Supermarket – we are so dependent on the internet that it is easy to assume the worst would happen without it. However, shutting down the public internet would not be easy. But such a scenario is so unlikely that considering it is no more than a “thought exercise” – but one well worth doing. Our resilience is boosted by a large number of independent ISPs, some of which have their own infrastructure, as well as the split between copper and fibre, and the separate networks. It is distributed network with many layers, routers, local exchanges – so it would be extremely hard to “take out” in its entirety, because there is no single point to do that. Even if fixed-line was down, there is three separate network access points for 2.5G, 3G and 4G, although the use of broadband networks for mobile data backhaul could be problematic.
There are several extreme scenarios in which the internet could conceivably be taken offline. The government could attempt to switch it off; catastrophe hit the supply; terrorist or a foreign government could attack infrastructure; or hackers could target key protocols. Another way the internet could go dark is if the power grid was disable – but there is ample backup systems, which can restart the grid in the event of complete loss of power. The most terrifying manner in which the internet could be disable is by violence. But still require a “very big, large-scale warfare event”. Simply ripping out cables from the ground could wreak havoc on a smaller scale. Hacker also can take down the internet with a very powerful distributed denial-of-service (DDoS) attack. Could you imagine losing a day [of service] which would be serious and would make a lot of headline news – and the government would use it as an excuse to put a lot more rules in place – but it is hard to see a DDoS attack lasting very long before it was isolated. A larger threat would be a direct attack on the routing system, the border gateway protocol (BGP), which not that robust.
If a multi-day outage occurred, the main problem would be communications – particularly for emergency services, and especially if a natural catastrophe or violent attack took place. It used to be that telephones and internet system were completely independent, so if the internet was down you could still phone somebody up. But unfortunately, some of the cellular phone system use the internet for their backhaul, and so you might find that you cannot call people.
If a prolonged outage took out internet shopping, along with debit- and credit-card payment system, cash would be key for stocking up – or panic buying – groceries and petrol. Whether or not we could take out cash would depend on the nature of the outage. If it was only the public internet that was offline, and not private networks, most cash machines would still work. While most of us do our banking online and take money out from cash machines, banks do still have branches.
When we look at worst-case scenario, as long as you can recover in a few days – one, two, three days – then it is not that bad. People will be able to do stuff in ad hoc ways. But if things last a week, it starts to become really critical. That is a very unlikely scenario.