CybersecurityIn our Wi-Fi world, the internet still depends on undersea cables

By Nicole Starosielski

Published 4 November 2015

Not many people realize that undersea cables transport nearly 100 percent of transoceanic data traffic. These lines are laid on the very bottom of the ocean floor. They’re about as thick as a garden hose and carry the world’s Internet, phone calls and even TV transmissions between continents at the speed of light. A single cable can carry tens of terabits of information per second. The cables we all rely on to send everything from e-mail to banking information across the seas remain largely unregulated and undefended. Any single cable line has been and will continue to be susceptible to disruption. And the only way around this is to build a more diverse system, because the thing that protects global information traffic is the fact that there’s some redundancy built into the system. But as things are, even though individual companies each look out for their own network, there is no economic incentive or supervisory body to ensure the global system as a whole is resilient. If there’s a vulnerability to worry about, this is it.

Recently a New York Times article on Russian submarine activity near undersea communications cables dredged up cold war politics and generated widespread recognition of the submerged systems we all depend upon.

Not many people realize that undersea cables transport nearly 100 percent of transoceanic data traffic. These lines are laid on the very bottom of the ocean floor. They’re about as thick as a garden hose and carry the world’s Internet, phone calls and even TV transmissions between continents at the speed of light. A single cable can carry tens of terabits of information per second.

While researching my book The Undersea Network, I realized that the cables we all rely on to send everything from e-mail to banking information across the seas remain largely unregulated and undefended. Although they are laid by only a few companies (including the American company SubCom and the French company Alcatel-Lucent) and often funneled along narrow paths, the ocean’s vastness has often provided them protection.

Far from wireless
The fact that we route Internet traffic through the ocean — amidst deep sea creatures and hydrothermal vents — runs counter to most people’s imaginings of the Internet. Didn’t we develop satellites and Wi-Fi to transmit signals through the air? Haven’t we moved to the cloud? Undersea cable systems sound like a thing of the past.

The reality is that the cloud is actually under the ocean. Even though they might seem behind the times, fiber-optic cables are actually state-of-the-art global communications technologies. Since they use light to encode information and remain unfettered by weather, cables carry data faster and cheaper than satellites. They crisscross the continents, too — a message from New York to California also travels by fiber-optic cable. These systems are not going to be replaced by aerial communications anytime soon.

A vulnerable system?
The biggest problem with cable systems is not technological — it’s human. Because they run underground, underwater and between telephone poles, cable systems populate the same spaces we do. As a result, we accidentally break them all the time. Local construction projects dig up terrestrial lines. Boaters drop anchors on cables. And submarines can pinpoint systems under the sea.