by Jennifer Ouellette, New Scientist
The internet is amazingly robust, but like any complex network is still prone to the occasional failure. A new analysis using network theory explains why the dark net – the hidden underbelly of the regular internet, invisible to search engines – is less vulnerable to attacks. The lessons learned could help inform the design of more robust communications networks in the future.
The regular internet’s design is deliberately decentralised, which makes it very stable under normal circumstances. Think of each site or server as a node, connected to numerous nodes around it, which in turn connect to even more nodes, and so on. Take out a node or two here or there and the network continues to function just fine. But this structure also makes it more vulnerable to a coordinated attack: take out many nodes at once, as happens during a distributed denial of service (DDoS) attack, and the result can be catastrophic failure that cascades through the entire network.
Researchers at Rovira i Virgili University in Spain used data from the Internet Research Lab at the University of California, Los Angeles to build their own model of the dark net. The researchers ran simulations to see how the model would react to three failure scenarios–random node failures, targeted attacks on specific nodes, and cascading failures throughout the network.
The researchers found an attack on the dark net would need to hit four times as many nodes to cause a cascading failure as on the regular Internet. They note this is because the dark net uses “onion routing,” a technique for relaying information that hides data in many layers of encryption.
Onion routing bounces the information through various intermediary nodes before delivering it to the desired location, which stops an attack from spreading too widely. The dark net’s lack of a high level of connectivity between powerful nodes also makes it more resilient. Read the article.